211 F.3d 1008 (7th Cir. 2000)
In the  United States Court of Appeals  For the Seventh Circuit
Nos. 98-4169, 98-4222

ROBERT E. COOPER and MARIANN POGGE, Trustee   of the Bankruptcy Estate of Robert E. Cooper,    Plaintiffs-Appellants, Cross-Appellees,v.CARL A. NELSON & CO., a corporation,    Defendant-Appellee, Cross-Appellant.
Appeal from the United States District Court  for the Central District of Illinois.  No. 94-1274--Joe B. McDade, Chief Judge.

Argued September 16, 1999
Decided March 7, 2000

1
As Amended on Denial of Rehearing and Rehearing En Banc June 1, 2000.


2
[Copyrighted Material Omitted][Copyrighted Material Omitted]


3
Before RIPPLE, MANION and DIANE P. WOOD, Circuit  Judges.


4
RIPPLE, Circuit Judge.


5
Robert E. Cooper1  brought this personal injury action against Carl  A. Nelson & Co. ("Nelson"), seeking damages for  an accident at a construction site. The case  proceeded to trial, and a jury verdict was  entered for Nelson. For the reasons set forth in  the following opinion, we reverse the judgment of  the district court and remand the case to the  district court for proceedings consistent with  this opinion.

I    BACKGROUND
A.  Facts

6
Nelson was the general contractor at the  construction of a new Wal-Mart in Macomb,  Illinois. Mr. Cooper was an electrician working  for one of Nelson's subcontractors. Workers at  the site were encouraged by Nelson to park in a  vacant lot at the existing Wal-Mart adjacent to  the construction site.2 This arrangement  required that they traverse a drainage ditch to  access the construction trailers. The bottom of  the ditch was spanned by planks, so that the  construction workers would not have to walk  through the bottom of the ditch. Rather, they had  to walk down an incline and then across the  planks and up an incline on the other side. The  incline down to the planks became muddy whenever  it rained, and it was difficult to maintain  footing. Consequently, Nelson laid pallets in  this area to afford workers additional traction.  The exact nature of the plank bridge and the  condition of the bottom of the ditch were  subjects of some dispute in the district court.


7
On July 7, 1992, Mr. Cooper slipped and fell  while traversing this drainage ditch. He claims  to have been knocked unconscious in his fall, and  does not recall exactly where he was when he  fell. He testified that it was raining at the  time of his accident and that both the ditch and  the planks were wet and slippery.

B.  Proceedings in the District Court

8
Mr. Cooper's initial amended complaint alleged  that he fell on the planks over the bottom of the  ditch. During discovery, he acknowledged that he  was not certain about the exact place of his  fall. He did not, however, further amend his  complaint to reflect this uncertainty. In ruling  on a motion for summary judgment filed by Nelson,  the district court determined that Mr. Cooper's  claim could not be sustained on the theory that  he had fallen on the planks themselves and,  therefore, granted summary judgment for Nelson.


9
The district court noted, however, that the  evidence produced at discovery suggested that Mr.  Cooper had fallen on the incline leading down  toward the location of the planks across the  bottom of the ditch. The district court therefore  vacated its grant of summary judgment and allowed  Mr. Cooper to amend his pleadings to allege that  he had fallen on the incline. In the new amended  pleading, Mr. Cooper alleged that he had fallen  on the muddy incline approaching the planks in  the ditch, not on the planks themselves.


10
Nelson later sought, through a motion in limine,  to preclude at trial any mention of Mr. Cooper's  having fallen on the planks. The district court  granted the motion. The district court noted that  the allegation in the second amended complaint  was that Mr. Cooper fell on the incline  approaching the planks and ruled that Mr. Cooper  ought to be bound at trial by that allegation.


11
Mr. Cooper sought to introduce at trial the  deposition testimony of medical professionals who  had examined him. Among those experts were Dr.  William Richardson, a specialist in internal  medicine affiliated with the St. Louis University  School of Medicine; Dr. Emre Kokmen, a board  certified neurologist at the Mayo Clinic in  Rochester, Minnesota; and Dr. Joshua Warach, a  board certified neurologist in Springfield,  Illinois. After a hearing to determine the  admissibility of this testimony under Daubert v.  Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579  (1993), the district court decided that the  testimony was not admissible because the  physicians had an inadequate foundation for  evaluating the cause of Mr. Cooper's injury.  Specifically, the district court pointed to the  physicians' finding that Mr. Cooper's 1992 fall  was the cause of his chronic pain syndrome and  other ailments. That finding was based on Mr.  Cooper's own statements to the physicians that he  had fallen in 1992, that before his fall he had  been healthy, and that after his fall his  physical condition had deteriorated.


12
Mr. Cooper also argued that, in addition to the  medical experts, Robert Bunch, a carpenter for  Nelson, should have been allowed to testify about  when a proper man bridge was built across the  ditch. Terry Lox, a supervisor for Nelson, was  allowed to testify that at the time of Mr.  Cooper's accident there was a man bridge across  the ditch, not merely some planks. Bunch would  have testified that he assisted in the  construction of a proper bridge after the  accident. The district court excluded the  testimony as evidence of a subsequent remedial  measure. See Fed. R. Evid. 407. The district  court also excluded a report from the Social  Security Administration finding that Mr. Cooper  was entitled to total disability benefits.


13
At the close of Mr. Cooper's case, the district  court granted Nelson summary judgment on Mr.  Cooper's claim that Nelson had willfully and  wantonly caused his injury. The case proceeded on  Mr. Cooper's negligence theory. After the  presentation of Nelson's case, the district court  instructed the jury that Nelson's duty was that  of a landowner. Mr. Cooper objected, claiming  that the contractor should not have been held to  the "passive" duty of care of a landowner, but  rather to a more active duty of ordinary care.  The jury returned a verdict for Nelson.

II    DISCUSSION

14
Mr. Cooper raises six distinct issues on appeal.  He argues that the district court incorrectly  granted summary judgment on the issue of the  place of the fall, that it administered faulty  jury instructions, and that it should not have  dismissed his willful and wanton injury claim.  The other three challenges relate to the district  court's evidentiary decisions: the rejection of  Robert Bunch's testimony, the refusal to admit  the Social Security Administration report, and  the decision under Daubert to exclude his  proffered medical testimony. We consider these  contentions in turn.

A.  Mr. Cooper's Fall

15
Mr. Cooper cannot remember whether he fell on  the slope approaching the planks over the ditch  or on the planks themselves. He originally  claimed that he slipped on the planks, but the  district court granted summary judgment for  Nelson on the ground that the evidence did not  support such an allegation but rather tended to  show that he slipped on the incline approaching  the location of the planks. Mr. Cooper then  amended his pleading to state that he had slipped  on the incline. Later, the court granted Nelson's  motion in limine to prevent Mr. Cooper from  offering testimony suggesting that he slipped on  the planks.


16
Before this court, Mr. Cooper submits that the  district court erred when it decided to take the  issue of whether he fell on the planks away from  the jury on the ground that there was no evidence  to support a verdict for Mr. Cooper on that  theory. First, contends Mr. Cooper, the district  court ought not to have granted summary judgment  to Nelson on the ground that the amended  complaint alleged solely that Mr. Cooper had  fallen on the planks, not the incline. Second,  continues Mr. Cooper, this initial error was  compounded when the district court, although  allowing an amendment of the pleadings, refused,  by granting the motion in limine, to allow the  jury to consider the possibility that he fell on  the planks. Mr. Cooper admits that his second  amended complaint, filed with leave of court  after the district court had granted summary  judgment on the first amended complaint, alleged  only that he had slipped on the incline, not on  the planks. He asks us to take into account,  however, that this complaint was filed only after  the district court had ruled that the evidence  would not support a jury finding that he had  slipped on the planks. Therefore, he submits, its  content was governed by the law of the case as  established in the district court's earlier  ruling.


17
Nelson replies that there was no evidence to  establish that Mr. Cooper slipped on the planks  and that the district court was therefore  justified in ruling as it did. It argues that, in  response to Nelson's summary judgment motion, Mr.  Cooper admitted that he had not fallen on the  planks but on the incline leading to the planks.  Indeed, even on this appeal, argues Nelson, Mr.  Cooper argues only that it is "just as likely"  that he fell on the planks as on the incline.


18
We believe that the district court should not  have precluded the jury from considering the  possibility that Mr. Cooper fell on the planks.  In the first amended complaint, Mr. Cooper  alleged, in more detail than was required by the  Rules, that he had "slipped among planks while  carrying materials for use on the job site  walking down the incline approaching the six foot  deep ditch and then fell onto the plank boards  which were inadequate to hold him and then onto  pallets laying in the ditch six feet below." R.85  at 9-10. When this allegation was challenged by  Nelson on summary judgment, Mr. Cooper admitted  that "[h]e did not fall on the planks. He fell  among the pallets located on the incline."3 In  the very same document, however, indeed, in the  preceding paragraph, Mr. Cooper gave a more  plenary description of his recollection of the  fall:


19
9.  He cannot say exactly where he fell because  he was knocked out by the fall. He remembers  coming off the flat ground getting ready to go  down the ditch; he remembers starting down the  incline. He could have been on the 2 by 10 planks  when he fell, but he cannot honestly answer yes  or no. (Cooper dep. 32).4


20
The district was correct when it concluded that  Mr. Cooper's initial amended complaint had been  too specific when it alleged only that he had  slipped on the incline.5 However, we think that  the district court went too far in its criticism  when it further concluded that the evidence of  record, including Mr. Cooper's own deposition  testimony, precluded the jury from considering  the possibility that he fell among the planks.


21
This misapprehension on the part of the district  court was partially corrected when the court  allowed Mr. Cooper to amend his complaint.  Unfortunately, as we see it, even at this stage  the district court's actions placed, as a  practical matter, inappropriate restrictions on  Mr. Cooper's effort to replead. The critical  document is the January 16, 1996 summary judgment  order; to get back into court, Mr. Cooper had to  overcome the deficiencies perceived by the  district court in his first amended complaint.  That summary judgment order was the only guidance  Mr. Cooper had on how he might revive his case.  In that document, the district court had not only  rejected the possibility that the jury might  conclude that he fell on the planks, it also  expressed clearly its own view of what the  evidence might show:


22
Defendant contends that Plaintiff cannot show  proximate cause here because there is no evidence  that the planks over the ditch had anything to do  with Plaintiff's injury. Plaintiff does nothing  to refute this claim. Rather, Plaintiff merely  changes the relevant facts in his Statement of  Disputed Facts, asserting that "[h]e did not fall  on the planks. He fell among the pallets located  on the incline." If the Court were to focus upon  these newfound facts, it would hold that the  testimony evinced during discovery is enough to  preclude summary judgment here. The theory would  be that Defendant's failure to remedy the unsafe  condition of the entire pathway (the inclines,  the pallets and the planks) during rainy periods  caused Cooper to traverse the incline on the mud,  thus causing him to slip and injure himself.


23
R.105 at 19-20 (emphasis added). As we have noted  earlier, this statement of the district court was  Mr. Cooper's only guidance on how to restart his  case. From our review of the record, we must  conclude, however, that the district court's  estimation of Mr. Cooper's case in that summary  judgment order rested on a misapprehension of the  record. For instance, although the court  correctly noted that "He testified that he fell  somewhere between the beginning of the slope to  halfway down the slope," Mr. Cooper also said  that he fell somewhere "between the crest of the  slope and halfway across the planks." Cooper  deposition at 39 (quoting the original  complaint). We cannot say that Mr. Cooper's  deposition testimony is accurately reported in  the court's statement that "Plaintiff knows that  he fell somewhere between the top of the incline  and half way down." R.105 at 20. Similarly  problematic is the district court's assertion  that "It is undisputed that Plaintiff did not  slip or fall on the planks themselves." Id. at  21. Mr. Cooper said specifically that he "could  have been" on the planks when he fell. Cooper  deposition at 32. His testimony was at least  partially corroborated by the deposition  testimony of his brother, whose testimony as to  Mr. Cooper's position after the fall at least  allowed the inference that he had fallen backward  from the planks onto the pallets.


24
As a general proposition, a district court has  the discretion to treat an allegation in a  party's pleading as a judicial admission. See  Taylor v. Monsanto Co., 150 F.3d 806, 809 (7th  Cir. 1998); Schott v. American Honda Motor Co.,  976 F.2d 58, 61 (1st Cir. 1992). A judicial  admission trumps evidence. See Murrey v. United  States, 73 F.3d 1448, 1455 (7th Cir. 1996);  Keller v. United States, 58 F.3d 1194, 1199 n.8  (7th Cir. 1995). Here, however, it would be  inappropriate to treat the allegations in the  second amended complaint as a binding admission  that ought to bind Mr. Cooper in the subsequent  trial. The allegations of that second amended  complaint are grounded in the district court's  earlier ruling that the evidence would not  support a jury finding that Mr. Cooper fell on  the planks, a ruling we think was based on a  misapprehension of the record. As we have noted  above, we believe that the evidence of record  made the exact place of the fall a jury issue  that ought not to have been excluded from the  trial of this matter.


25
Nelson argues that we should not consider Mr.  Cooper's argument that he fell on the planks  rather than the incline. Nelson contends that, if  Mr. Cooper wanted to preserve the option of  making such an argument, he should have appealed  the district court's initial grant of summary  judgment rather than seeking permission to  replead in conformity with the district court's  view of the evidence. Because, in any event, the  judgment under review cannot stand due to  instructional and evidentiary error, we believe  that, in a retrial of the case, none of the  policy concerns animating the law of the case  doctrine require that the district court's  initial misapprehension of the evidence ought to  control. See Alston v. King, 157 F.3d 1113, 1116  (7th Cir. 1998) (holding that the law of the case  is only a presumption whose strength varies with  circumstances); see also United States v. United  States Smelting Co., 339 U.S. 186, 199 (1950).


26
B. Nelson's Duty of Care and the  Resulting Jury Instructions


27
In this diversity case, the nature of Nelson's  duty to Mr. Cooper is governed by Illinois law,  and in Illinois the existence of a duty is a  question of law. See Reid v. Norfolk & W. Ry.  Co., 157 F.3d 1106, 1110 (7th Cir. 1998);  Rodriguez v. Norfolk & W. Ry. Co., 593 N.E.2d  597, 607 (Ill. App. Ct. 1992). We review such  questions de novo. See Khan v. Gallitano, 180  F.3d 829, 837 (7th Cir. 1999). Although the  existence of a duty must be determined as a  matter of law, the question of whether there was  a breach of that duty and an injury proximately  caused by that breach are questions of fact for  the jury. See Rodriguez, 593 N.E.2d at 607. An  error in jury instructions therefore can be  reversible error if it misinforms the jury about  the applicable law. See Bruno v. City of Crown  Point, 950 F.2d 355, 360 (7th Cir. 1991), cert.  denied, 505 U.S. 1207 (1992); Schranz v. Halley,  448 N.E.2d 601, 603 (Ill. App. Ct. 1983).


28
The district court's instructions to the jury  asked it to consider whether Nelson had exercised  reasonable care, the standard applied to  landowners in Illinois for injuries occurring on  their land. See Lewis E. v. Spagnolo, 710 N.E.2d  798, 815 (Ill. 1999); Ward v. K-Mart Corp., 554  N.E.2d 223, 229 (Ill. 1990). Illinois has adopted  the rules set forth in sections 343 and 343A of  the Restatement (Second) of Torts regarding the  duty of possessors of land to their invitees.  Therefore, as a general rule, a landowner in  Illinois is only liable for harm caused to  invitees by a condition on his land if he:


29
(a)  knows or by the exercise of reasonable care  would discover the condition, and should realize  that it involves an unreasonable risk of harm to  such invitees, and


30
(b)  should expect that they will not discover or  realize the danger, or will fail to protect  themselves against it, and


31
(c)  fails to exercise reasonable care to protect  them against the danger.


32
Genaust v. Illinois Power Co., 343 N.E.2d 465,  472 (Ill. 1976) (quoting Restatement (Second) of  Torts sec. 343); see also Deibert v. Bauer Bros.  Const. Co., 566 N.E.2d 239, 241 (Ill. 1990)  (quoting Genaust); Ward, 554 N.E.2d at 229  (same). As a general rule, therefore, landowners  in Illinois are not liable to invitees when  invitees should have realized the danger and  could have protected themselves against it; the  landowner's duty is only to rid the land of  unreasonable dangers. As the Supreme Court of  Illinois pointed out in Deibert, this general  rule is subject to an exception set forth in sec.  343A of the Restatement. See 566 N.E.2d at 243.  That section states:


33
A possessor of land is not liable to his  invitees for physical harm caused to them by any  activity or condition on the land whose danger is  known or obvious to them, unless the possessor  should anticipate the harm despite such knowledge  or obviousness.


34
Restatement (Second) of Torts sec. 343A(1), at  218 (1965), quoted in 566 N.E.2d at 241. In the  case before us, the general contractor, Nelson,  stands in the place of the landowner and, for  purposes of our analysis, is the possessor of the  land. See Deibert, 566 N.E.2d at 240-43.


35
We think that two considerations lead to the  conclusion that the duty of Nelson was not simply  that set forth in sec. 343 of the Restatement  (Second) of Torts. First, as the Supreme Court of  Illinois made clear in Deibert, the duty of the  landowner is set forth not only in sec. 343 but  also in the exception to that general rule in  sec. 343A. See id. at 241-42. This latter  provision requires that the possessor of the land  remedy an activity or condition on the land  which, although known and obvious to the invitee,  may still cause that individual harm. Here,  Nelson had undertaken to construct a walkway of  pallets to permit the workers to traverse the  incline and a bridge of planks to cross the  bottom of the ditch. According to the evidence of  record, the jury was entitled to believe Mr.  Cooper's allegations that the wooden walkway had  become so muddy that he was required to walk down  the unprotected incline which also posed a danger  because of its muddy condition. The jury was  entitled to consider whether the condition of the  premises was such that Nelson was required to  anticipate that workers such as Mr. Cooper might  avoid the mud on the pallets and consider the  unprotected incline to be at least as safe a  passage as the one prepared by Nelson.


36
Given the factual context of this case, the contractual provision governing the  relationship of the general contractor, Nelson,  to the subcontractor also appears to have set a  standard of care somewhat higher than the one set  forth in the Restatement sections. The  contractual provision states that the contractor  "shall take reasonable precautions for safety of  . . . employees on the Work," Appellant's Br. at  21. In interpreting this section, we must be  careful not to interpret the contractual  provisions in such a way as to expand the duties  of the contractor beyond the scope of the duties  described in the contract. See American States  Ins. Co. v. A.J. Maggio, Inc., 593 N.E.2d 1083,  1086 (Ill. App. Ct. 1992).6 In American States,  the Illinois court determined that a contractual  provision that imposed a duty to keep the work  area in reasonably safe condition imposed no  greater duty on the possessor of the land than  the common law duty stated above. By contrast,  the contractual duty here places the affirmative  duty on the possessor of the land "to take  reasonable precautions" for the safety of the  workers. In our view, the jury was entitled to  consider whether Nelson had breached its  obligation by the manner in which the pallet  walkway was constructed or by permitting its  condition to deteriorate.


37
In Ward, the Supreme Court of Illinois noted  that, in ascertaining whether a possessor of land  owes a duty of care to an invitee, a court must  take into consideration the magnitude of the  burden of guarding against the injury, and the  consequences of placing that burden upon the  defendant, as well as the likelihood of injury  and the possible serious nature of such an  injury. See 554 N.E.2d at 226-27. Here, the  existence of a duty of care cannot be decided in  abstracto but must take into account the  relationship of the contractor to the  subcontractor and the undertakings of the former  for the employees of the latter. Here, the  allegation is that the prime contractor breached  its obligation to these employees, including Mr.  Cooper, by failing to maintain a proper walkway  to the job site, by permitting it to become  covered with quantities of mud that rendered it  useless, and by requiring the workers to try  other ways of making the same passage. In our  view, these allegations implicate the policy  concerns noted by the Supreme Court of Illinois  in much the same way as those cases that  articulate a higher standard of care for  landowners who place a foreign substance on their  land. See Donoho v. O'Connell's, Inc., 148 N.E.2d  434, 439 (Ill. 1958); Wind v. Hy-Vee Food Stores,  Inc., 650 N.E.2d 258, 262 (Ill. App. Ct. 1995).


38
On the record before us, therefore, we must  conclude that the jury was not instructed  properly with respect to whether Nelson had  breached its duty of care.7

C.  Mr. Cooper's Willful and Wanton Claim

39
At the close of Mr. Cooper's evidence, the  district court granted a directed verdict for  Nelson on Mr. Cooper's willful and wanton claims.  We review de novo the decision to grant a  directed verdict, reviewing the evidence in the  light most favorable to Mr. Cooper. See Payne v.  Milwaukee County, 146 F.3d 430, 432 (7th Cir.  1998); Bowlen v. United States, 956 F.2d 723, 727  (7th Cir. 1992).


40
Because we believe that Mr. Cooper ought to be  permitted to argue that he fell on the planks  over the ditch, not on the slope approaching the  planks, we also believe that the directed verdict  on the issue of whether Nelson willfully and  wantonly caused his injury cannot stand at this  point in the litigation. The district court will  have to revisit this matter in due course. To  prevail on this theory, Mr. Cooper must show  either that Nelson actually or deliberately  intended to harm him, or that Nelson was utterly  indifferent to or showed a conscious disregard  for his personal safety. See Pfister v. Shusta,  657 N.E.2d 1013, 1016 (Ill. 1995); Bowden v. Cary  Fire Protection Dist., 710 N.E.2d 548, 552 (Ill.  App. Ct. 1999). Relying on the testimony of other  construction workers at the site, he argues that,  when a landowner knows of a dangerous condition  and fails to remedy it, he has exhibited a  reckless disregard for the safety of others that  leads to his liability for willful or wanton  injuries. See Schneiderman v. Interstate Transit  Lines, 69 N.E.2d 293, 300 (Ill. 1946). As we have  held in the preceding section, Mr. Cooper ought  to be permitted to argue that he slipped not on  the incline but on the planks. Therefore, he  should not be foreclosed from arguing that  Nelson's decision to utilize this configuration  rather than a man bridge constituted willful or  wanton behavior.

D.  Testimony of Robert Bunch

41
Although the matter may not arise again in the  same context, we shall address, for the sake of  judicial economy, the district court's decision  not to admit the testimony of Robert Bunch that a  man bridge was built over the area after Mr.  Cooper's fall.


42
The district court admitted testimony from Terry  Lox, a Nelson supervisor, that on the day of Mr.  Cooper's injury, the ditch was spanned not by  planks, but by a man bridge. The court instructed  the jury that it was to consider Lox's testimony only for the purposes of determining Lox's  credibility. The testimony was limited because,  in light of the determination that Mr. Cooper  slipped on the incline, the exact nature of the  bridge at the time of the incident was  irrelevant. Mr. Cooper then sought to contradict  Lox through testimony by Robert Bunch, another  worker at the site, that Bunch assisted Lox with  the construction of a bridge after Mr. Cooper's  injury. The district court would not allow this  testimony pursuant to Federal Rule of Evidence  407, which bars testimony about subsequent  remedial measures for the purposes of proving  negligence. The district court's rulings on  evidentiary decisions are reviewed for an abuse  of discretion. See White v. United States, 148  F.3d 787, 791 (7th Cir. 1998); United States v.  Beyer, 106 F.3d 175, 179 (7th Cir. 1997).


43
The district court did not abuse its discretion  in excluding Bunch's testimony. There was nothing  to prevent Mr. Cooper from contradicting Lox's  story, or attacking Lox's credibility, by  introducing evidence that there was no bridge at  the time of Mr. Cooper's injury. At Bunch's  deposition, Mr. Cooper's counsel did not ask  Bunch to describe the condition of the ditch  before the accident, which would have been  permissible. Instead, he asked Bunch to describe  his assistance with the construction of a bridge  after the accident, which was not. The district  court did not abuse its discretion in excluding  the evidence.


44
E.  The Social Security Administration  Report


45
Mr. Cooper sought to introduce a Social Security  Administration report, pursuant to Federal Rule  of Evidence 803(8)(C), the hearsay exception for  government reports. An administrative law judge  of the Social Security Administration determined  that Mr. Cooper's chronic pain syndrome entitled  him to total disability benefits. His counsel  explained that he wished to argue to the jury  that Mr. Cooper's eligibility for social security  disability payments demonstrated the severity of  his injury and, therefore, was relevant to the  measure of damages. The district court refused to  admit the report into evidence, finding it both  irrelevant and more prejudicial than probative  pursuant to Federal Rule of Evidence 403. When  reviewing the district court's evidentiary  decisions, we employ an abuse of discretion  standard and consequently give great deference to  the trial court. See Merriweather v. Family  Dollar Stores of Ind., 103 F.3d 576, 580 (7th  Cir. 1996); Littlefield v. McGuffey, 954 F.2d  1337, 1342 (7th Cir. 1992).


46
We have noted that the district court retains  significant discretion to exclude administrative  findings that meet the standards of Federal Rule  of Evidence 803(8)(C). See Halloway v. Milwaukee  County, 180 F.3d 820, 827 n.9 (7th Cir. 1999);  see also Johnson v. Yellow Freight Sys., 734 F.2d  1304, 1309 (8th Cir.) ("In our view, it would be  ill-advised to shackle the discretion of trial  judges with a rule of per se admissibility."),  cert. denied, 469 U.S. 1041 (1984). Evidence  admissible under Rule 803(8)(C) is still subject  to exclusion on other grounds, such as relevancy.  See Beech Aircraft v. Rainey, 488 U.S. 153, 167-  68 (1988); Paolitto v. John Brown E.&C., Inc.,  151 F.3d 60, 64 (2d Cir. 1998). The district  court here decided that a finding that Mr. Cooper  met the Social Security Administration's  definition of totally disabled was irrelevant  because the jury would be applying a different  standard. Our review of the record leaves us with  some doubt, however, as to whether the district  court and counsel miscommunicated about the  narrow purpose for which Mr. Cooper sought  admission of the document. Even on this narrow  ground, the district court may have believed that  any probative value of the report was outweighed  by its potential to confuse the jury. If the  issue arises again on remand, the district court  is free to revisit the issue.

F.  Medical Expert Testimony

47
At trial, Mr. Cooper attempted to establish that  he was suffering from chronic pain syndrome  ("CPS") and that this condition was caused by his  fall. He offered the testimony of three medical  expert witnesses to substantiate his submission.  The three witnesses--Dr. William Richardson, Dr.  Emre Kokmen, and Dr. Joshua D. Warach--were  prepared to testify about the CPS suffered by Mr.  Cooper. The parties agreed that the district  court's decision on the admissibility of Dr.  Richardson's testimony also would apply to Dr.  Kokmen and Dr. Warach because the question  considered by the court--the propriety of  reliance on Mr. Cooper's statements to the  physicians in determining causation--was the same  for each of them.


48
The district court refused to admit the  testimony. Because each physician relied on Mr.  Cooper's statements about his past medical  history as the basis for a diagnosis that Mr.  Cooper's fall caused his CPS, the district court  concluded that the physicians had no scientific  basis for their testimony. We believe that the  district court assumed an overly aggressive role  as "gatekeeper" and that the jury ought to have  been allowed to assess the physicians' assertion  that trauma from the fall caused Mr. Cooper's  pain.


49
Dr. Richardson, a pain specialist associated  with St. Louis University, treated Mr. Cooper for  chronic pain, beginning on August 30, 1994. In  his deposition testimony, he stated that trauma  is a recognized cause of chronic pain syndrome.  He also described his examination of Mr. Cooper,  which included a physical examination and a self-  reported medical history from the patient. In the  course of that medical history, Mr. Cooper told  him about his fall at the Nelson construction  site. Mr. Cooper also told Dr. Richardson that,  after the accident, he began experiencing pain in  his mid-thoracic area, his buttocks and thighs,  his right leg, his neck, and his shoulders, and  that he also suffered headaches. In his  diagnosis, Dr. Richardson concluded that Mr.  Cooper was suffering from chronic musculoskeletal  pain. Dr. Richardson further said that, based on  Mr. Cooper's statement that he had been free of  pain before the fall, the pain was caused by the  fall. Dr. Richardson also explained that the  cause of Mr. Cooper's trauma was irrelevant to  him in prescribing a course of treatment and  that, therefore, he did not inquire further as to  the cause of Mr. Cooper's CPS.


50
The district court, attempting to fulfill the  mandate of  Daubert v. Merrell Dow  Pharmaceuticals, Inc., 509 U.S. 579 (1993),  essentially identified four issues that it  believed needed to be resolved before Dr.  Richardson's testimony could be admitted. Those  issues were:


51
1)  Is there a scientific basis for diagnosing  a patient as having chronic pain syndrome?


52
2)  If so, is there a scientific basis for  finding that trauma could cause chronic pain  syndrome?


53
3)  If so, is there a scientific basis for  finding that Mr. Cooper has chronic pain  syndrome?


54
4)  If so, is there a scientific basis for  finding that Mr. Cooper's chronic pain syndrome  was caused by trauma?


55
As this case comes to us, Nelson has admitted  that the diagnosis of CPS is generally, although  not universally, recognized among members of the  medical profession. It recognizes that, among  physicians who believe that CPS is a disease,  trauma is generally recognized as a cause of that  condition. It also acknowledges that Dr.  Richardson may have employed a differential  diagnosis to determine whether Mr. Cooper suffers  from CPS. Nelson therefore asks us to focus on  the fourth inquiry: whether there was a  scientific basis for concluding that Mr. Cooper's  CPS was caused by the fall down the hill. Nelson  contends that not only could Dr. Richardson not  rely on a patient's statements to prove  causation, but, in this case, Mr. Cooper had lied  about the nature of the incident that allegedly  caused his injuries and had lied further about  being free of pain before the incident. Nelson  contends, therefore, that the court properly  refused to admit Dr. Richardson's testimony on  the issue of causation.


56
More specifically, Nelson stresses that Dr.  Richardson admitted that not all CPS patients can  point to a particular event as the cause of their  condition and further admitted that emotional  factors have been known to play a role in the  onset of the condition. Nelson further contends  that Dr. Richardson had not taken into account  the possible effect of such other factors in Mr.  Richardson's life on the onset of the condition.  Indeed, argues Nelson, Dr. Richardson made no  critical evaluation of the cause of Mr. Cooper's  CPS because it was not necessary to his treatment  of the condition that he know with any certainty  its cause. Before this court, Nelson argues that  Dr. Richardson's "post hoc, propter hoc"  determination of cause, although perhaps an  acceptable methodology in cases in which the  mechanism of injury is understood, is not  adequate in cases such as this one in which that  mechanism is not understood.


57
We think that Nelson suggests, in the context of  this case, an overly demanding gatekeeping role  for the district court. Indeed, Nelson seems to  agree that, in clinical medicine, the methodology  of physical examination and self-reported medical  history employed by Dr. Richardson is generally  appropriate. Although it disputes the  acceptability of such an approach in the case of  conditions whose etiologies are less specific, it  suggests no alternative that could be employed by  the conscientious clinical physician in this  situation. Certainly, when the asserted cause of  the patient's condition is a phenomenon that  requires specialized scientific knowledge, "an  insightful, even an inspired, hunch" will not  suffice. Rosen v. Ciba-Geigy Corp., 78 F.3d 316,  319 (7th Cir.) (testimony of treating physician  that nicotine patch worn for three days was a  cause for myocardial infarction properly  excluded), cert. denied, 519 U.S. 819 (1986). See  also Bradley v. Brown, 42 F.3d 434, 438 (7th Cir.  1994) (testimony of physician that multiple  chemical sensitivity was the result of pesticide  exposure properly excluded); O'Conner v.  Commonwealth Edison Co., 13 F.3d 1090, 1107 (7th  Cir.) (physician's testimony that radiation  exposure caused plaintiff's cataracts properly  excluded), cert. denied, 512 U.S. 1222 (1994);  Porter v. Whitehall Labs., Inc., 9 F.3d 607, 614  (7th Cir. 1993) (treating physician's testimony  that renal failure caused by ibuprofen was  properly excluded). In Rosen, Chief Judge Posner  emphasized that the purpose of the rule announced  in Daubert "was to make sure that when scientists  testify in court they adhere to the same  standards of intellectual rigor that are demanded  in their professional work." 78 F.3d at 318.  Indeed, Rule 703 of the Federal Rules of Evidence  explicitly permits reliance on material  "reasonably relied upon by experts in the  particular field in forming opinions or  inferences." Fed. R. Evid. 703. Our case law has  recognized that experts in various fields may  rely properly on a wide variety of sources and  may employ a similarly wide choice of  methodologies in developing an expert opinion.  See United States v. Lundy, 809 F.2d 392, 395-96  (7th Cir. 1987) (noting that arson experts  regularly rely upon "interviews with many  witnesses to a fire" as a "standard investigating  technique in cause and origin inquiries"); see  also United States v. Lawson, 653 F.2d 299, 302  n.7 (7th Cir. 1981), cert. denied, 454 U.S. 1150  (1982). Here, Dr. Richardson essentially  testified that a patient history indicating  freedom from pain before a given event followed  by pain of the type experienced and observed  following the incident was a sufficient basis for  diagnosis and treatment of Mr. Cooper's chronic  pain syndrome.


58
The possibility of Mr. Cooper's CPS being  attributable to a factor other than the fall is a  subject quite susceptible to exploration on  cross-examination by opposing counsel. Similarly,  the accuracy and truthfulness of the underlying  medical history is subject to meaningful  exploration on cross-examination and ultimately  to jury evaluation. Therefore, Nelson's  contention that other conditions of Mr. Cooper's  might have caused his CPS goes to the weight of  the medical testimony, not its admissibility.  Notably, on cross-examination of Dr. Richardson,  Nelson elicited testimony that Dr. Richardson had  really done no investigation into the causes of  Mr. Cooper's CPS; Nelson presented evidence that  Mr. Cooper suffered physical maladies before July  7, 1992; it also presented evidence that Mr.  Cooper had been less than truthful in the history  he submitted to Dr. Richardson. This evidence  would permit a jury to conclude that the fall did  nothing to cause CPS. The proper method of  attacking evidence that is admissible but subject  to doubt is to cross-examine vigorously, to  present contrary evidence, and to give careful  instructions on the burden of proof. Daubert  acknowledged the continuing vital role that  "[v]igorous cross-examination, presentation of  contrary evidence, and careful instruction on the  burden of proof," 509 U.S. at 596, are to play in  the trier of fact's ultimate evaluation of  admissible but shaky evidence. See Daubert, 509  U.S. at 596. See also Rushing v. Kansas City S.  Ry. Co., 185 F.3d 496, 507 n.10 (5th Cir. 1999);  Allison v. McGhan Med. Corp., 184 F.3d 1300, 1311  (11th Cir. 1999); Freeman v. Case Corp., 118 F.3d  1011, 1017 (4th Cir. 1997), cert. denied, 522  U.S. 1069 (1998). All of these tools were  utilized by Nelson.


59
Here, a physician employed the accepted  diagnostic tool of examination accompanied by  physical history as related by the patient.8 In  this case, this methodology was acceptable under  the gatekeeping requirements of Daubert. We are  aware that, although Daubert is concerned  primarily with the issue of methodology, not  conclusions, "conclusions and methodology are not  entirely distinct from one another. Trained  experts commonly extrapolate from existing data."  General Elec. Co. v. Joiner, 118 S. Ct. 512, 519  (1997). Although a court "may conclude that there  is simply too great an analytical gap between the  data and the opinion proffered," id., no such  suggestion has been made here. Accordingly, in  the circumstances presented here, Dr.  Richardson's testimony should not have been  excluded under Daubert solely on the ground that  his causation diagnosis was based only on his  patient's self-reported history.


60
On remand, the district court must revisit the  issue of the admissibility of the testimony of  the physicians and must determine the  admissibility of the proffered evidence in  accordance with this decision. The district court  retains, of course, the discretion to exclude  portions of the depositions that are inconsistent  with other Federal Rules of Evidence.

G.  Comparative Fault

61
Because we remand this case for a new trial, we  must consider Nelson's cross-appeal. After the  close of evidence, the district court granted a  directed verdict for Mr. Cooper on the issue of  comparative fault, finding no evidence to suggest  that there was an alternate route for Mr. Cooper  to use to get around the ditch. Nelson argues  that there was testimony that Mr. Cooper knew the  ditch was dangerous, and knew of ways around the  ditch, and that, therefore, the jury should have  had a chance to consider the question of  comparative fault. We review the district court's  decision de novo. See Payne, 146 F.3d at 432;  Bowlen, 956 F.2d at 727.


62
A manager for Nelson, James Quickstead,  testified that there was an alternative area for  workers to park that would not require them to  walk over the ditch. He acknowledged, however,  that the Wal-Mart parking lot was the primary  parking lot. Robert Bunch testified that some of  Nelson's men took a truck around the ditch and  that, on one occasion, a Nelson truck carried his  tools around the ditch. Mr. Cooper responds that  Bunch's testimony discussed the time period after  Mr. Cooper's injury. Although Nelson is correct  that Mr. Cooper was aware of the danger of the  ditch and proceeded despite it, Mr. Cooper parked  in the primary parking lot for Nelson workers,  and crossed the primary route used by Nelson  workers from that lot to the work site. We agree  with the district court that his choice to do so  does not implicate the doctrine of comparative  fault.

Conclusion

63
For the foregoing reasons, the jury verdict is  reversed, and the case is remanded for further  proceedings consistent with this opinion.9

REVERSED and REMANDED


Notes:


1
 Although the case is brought by the injured party  and the trustee of his bankruptcy estate, for the  reader's convenience, we shall refer solely to  Mr. Cooper throughout this opinion.


2
 Alternative parking was available, but the lot  described in the text was the primary parking  lot.


3
 Plaintiff's statement of genuine issues of  material fact precluding summary judgment at  I.C.10.


4
 Id. at I.C.9.


5
 We note that in a notice pleading regime, the  plaintiff is often well advised when filing his  complaint to limit the detail of its factual  averments. See American Nurses' Ass'n v. State of  Illinois, 783 F.2d 716, 724 (7th Cir. 1986) ("A  plaintiff who files a long and detailed complaint  may plead himself out of court by including  factual allegations which if true show that his  legal rights were not invaded.").


6
 See also Pippin v. Chicago Hous. Auth., 399  N.E.2d 596, 599 (Ill. 1979) ("The Authority's  duty was limited by the extent of the  undertaking"); Kotarba v. Jamrozik, 669 N.E.2d  1185, 1188 (Ill. App. Ct. 1996); Perkaus v.  Chicago Catholic High Sch. Athletic League, 488  N.E.2d 623, 628 (Ill. App. Ct. 1986).


7
 It is also clear that counsel properly preserved  his objection to the instruction given by the  court. R.408 at 286-87. See Lawson v. Trowbridge,  153 F.3d 368, 372 (7th Cir. 1998).


8
 Fed. R. Evid. 803(4) n.4 (statements of external  cause of pain not hearsay because of  trustworthiness).


9
 Nelson has asked that Mr. Cooper be sanctioned  for bringing a frivolous appeal. In light of our  disposition of the case, Nelson's motion must be  denied.


