                                                        [DO NOT PUBLISH]


            IN THE UNITED STATES COURT OF APPEALS

                    FOR THE ELEVENTH CIRCUIT
                     ________________________                  FILED
                                                      U.S. COURT OF APPEALS
                                                        ELEVENTH CIRCUIT
                            No. 08-13810                  December 16, 2008
                        Non-Argument Calendar            THOMAS K. KAHN
                      ________________________                CLERK

                 D. C. Docket No. 06-00179-CV-HLM-4

DAVID R. WILSON,
CHARLENE WILSON,

                                                        Plaintiffs-Appellants,


                                 versus


TASER INTERNATIONAL, INC.,

                                                        Defendant-Appellee.


                      ________________________

               Appeal from the United States District Court
                  for the Northern District of Georgia
                    _________________________

                          (December 16, 2008)

Before CARNES, WILSON and KRAVITCH, Circuit Judges.

PER CURIAM:
      Plaintiff-Appellants David and Charlene Wilson (the “Wilsons”) brought

claims for products liability, punitive damages, and loss of consortium against

Defendant-Appellee TASER International, Inc. (“TASER”). The Wilsons assert

that TASER, the manufacturer of an electrical stun gun, failed to warn of the

allegedly known risk that exposure to the weapon could cause fractures and, as a

result, Georgia State Trooper David Wilson suffered a fractured spine during a

TASER training exercise. The district court granted TASER’s motion for

summary judgment, which the Wilsons now appeal. For the following reasons, we

AFFIRM.

                                BACKGROUND

      The facts of this case, as supported by the evidence taken in the light most

favorable to the Wilsons, are as follows:

      On September 7, 2004, David Wilson attended a TASER certification class

in Forsyth, Georgia at the Georgia Public Safety Training Center. Wilson was

shown a slide presentation which caused him to believe that no injuries, except

due to falls, had occurred during training. Wilson volunteered to be shocked as

part of his training and was assured that he would be properly spotted and

therefore would not be injured. Wilson was held by three spotters and shot in the

back with a TASER by the trainer. Wilson described the pain following this

                                            2
exposure as “unbelievable” and claims that he continued to experience intense

pain after the shock was over. An ambulance was called and Wilson was taken to

the hospital emergency room. The emergency room physician recommended that

Wilson be admitted for pain control. Wilson, however, declined to be admitted,

was given prescriptions for narcotic pain medication and was discharged with

instructions to see his personal physician.

      The following day, Wilson went to see Dr. Edward Meier, who specializes

in family practice and occupational medicine. Dr. Meier noted that Wilson had

continued to experience pain even after he was given Morphine, Percocets and

muscle relaxers and that his pain was well out of proportion with the objective

x-ray findings that he received from the hospital. Dr. Meier treated Wilson for

back pain and muscle spasms and recommended physical therapy. On October 5,

2004, Wilson again visited Dr. Meier, who noted that Wilson was “doing a lot

better and improved.”

      On October 28, 2004, Dr. Meier’s partner, Dr. Michael Jackson, referred

Wilson for an MRI. The MRI revealed two compression fractures of his thoracic

spine. Dr. Jackson referred Wilson to orthopedic specialist Dr. Scott Bowerman

for consultation and treatment. On August 23, 2005 and again on April 18, 2006,




                                          3
Dr. Meier, after consulting with Dr. Bowerman, certified Wilson as unable to

return to work due to the compression fractures caused by the TASER exposure.

      Thereafter, the Wilsons brought their claims against TASER in district

court, alleging that the failure to warn of a known risk caused David Wilson’s

compression fracture. At the close of discovery, TASER filed a motion for

summary judgment, asserting that the Wilsons failed to present sufficient evidence

of causation. The Wilsons responded to TASER’s motion and attached the

affidavit of treating physician Dr. Meier, who opined that the cause of Wilson’s

injury was the TASER exposure. TASER objected to this affidavit, asserting that

Federal Rule of Civil Procedure 26(a)(2)(B) required the Wilsons to disclose Dr.

Meier as an expert witness and submit an expert report for Dr. Meier.

      The district court entered an order denying TASER’s motion for summary

judgment, but directing the Wilsons to obtain an expert report from Dr. Meier

regarding his causation opinion and to make Dr. Meier available for a deposition.

The Wilsons obtained an expert report from Dr. Meier and TASER deposed him.

      In his expert report, Dr. Meier described his treatment of Mr. Wilson then

stated that “[b]ased on my review of the records from the Monroe County Hospital

Emergency Room, the records from physical therapy, the radiological report, Dr.

Bowerman’s consultation, and my treatment of Mr. Wilson which began the day

                                         4
following his injury and continued for more than two months afterward, and based

upon my medical training and experience, and to a reasonable degree of medical

certainty, the cause of Mr. Wilson’s compression fracture and his severe back pain

was due to exposure to the TASER during the training exercise on September 7,

2004.” Dr. Meier further noted that “[i]t is well documented in the medical

literature that fractures may be caused by electric shock” and cited to the opinion

of a Dr. Brown and to an attached article entitled “Thoracic Compression

Fractures as a Result of Shock From a Conducted Energy Weapon: A Case

Report.”

      TASER filed a Daubert motion to exclude Dr. Meier’s expert testimony

regarding causation, claiming that his opinions on that subject are unreliable.1 The

district court granted TASER’s motion and excluded Dr. Meier’s expert testimony

regarding causation. The court explained that although Dr. Meier was qualified to

offer opinions concerning medical causation, his opinion in this case was

unreliable because the opinions of his colleagues, upon which he relied, were

speculative and conclusory and because the article and one case study referred to

by Dr. Meier did not provide reliable support for his opinion.




      1
          Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993).
                                          5
      Thereafter, the Wilsons moved to reopen discovery so as to depose Dr.

Bowerman as their expert on causation. The court denied this motion as untimely.

      TASER again moved for summary judgment, arguing that the Wilsons

presented insufficient evidence of causation. The district court found that medical

expert testimony was necessary to support the causation element of the Wilsons’

failure to warn claim, and that because no admissible medical expert testimony

regarding causation had been presented, that claim failed. Without the failure to

warn claim, the district court found that the loss of consortium and punitive

damages claims were also deficient as a matter of law. Accordingly, the district

court granted summary judgment to TASER on all of the Wilsons’ claims. The

Wilsons filed a timely appeal, claiming that the district court erred (1) in excluding

Dr. Meier’s causation testimony and (2) in granting summary judgment to

TASER.2

                            STANDARD OF REVIEW




      2
         The Wilsons also argue that the district court erred in requiring Dr. Meier
to provide an expert report because Rule 26(a)(2)(B) does not require treating
physicians to submit expert reports regarding their diagnoses. We conclude,
however, that this argument is not germane to the appeal. The district court did
not exclude Dr. Meier’s testimony for failure to submit an expert report; rather,
after allowing extra time in which to file an expert report, the district court
excluded Dr. Meier’s testimony as unreliable.
                                          6
      We review the district court’s grants of summary judgment de novo,

reviewing all facts and reasonable inferences in the light most favorable to the

nonmoving party, and applying the same standard as the district court. Rodgers v.

Singletary, 142 F.3d 1252, 1253 (11th Cir. 1998); Hale v. Tallapoosa County, 50

F.3d 1579, 1581 (11th Cir. 1995). A grant of summary judgment is appropriate “if

the pleadings, depositions, answers to interrogatories, and admissions on file,

together with the affidavits, if any, show that there is no genuine issue as to any

material fact and that the moving party is entitled to a judgment as a matter of

law.” Fed. R. Civ. P. 56(c). “If the record presents factual issues, the court must

not decide them; it must deny the motion and proceed to trial.” Clemons v.

Dougherty County, Ga., 684 F.2d 1365, 1369 (11th Cir. 1982). A grant of

summary judgment may be upheld on any basis supported by the record.

Fitzpatrick v. City of Atlanta, 2 F.3d 1112, 1118 (11th Cir. 1993).

      We review a decision to exclude expert testimony under Daubert for abuse

of discretion. General Elec. Co. v. Joiner, 522 U.S. 136, 138-39 (1997). This

deferential standard is not relaxed even though a ruling on the admissibility of

expert evidence may be outcome-determinative. Id. at 142-43. “Cases arise where

it is very much a matter of discretion with the court whether to receive or exclude

the evidence; but the appellate court will not reverse in such a case, unless the

                                          7
ruling is manifestly erroneous.” Id. (quoting Spring Co. v. Edgar, 99 U.S. 645

(1878)); see also N.V. Maatschappij Voor Industriele Waarden v. A.O. Smith

Corp., 590 F.2d 415, 418 (2d Cir. 1978) (pointing out that Rule 702, although

broadening “the range of admissible expert testimony,” does not alter the

“manifestly erroneous” standard of review). The burden of laying the proper

foundation for the admission of the expert testimony is on the party offering the

expert, and admissibility must be shown by a preponderance of the evidence.

Daubert, 509 U.S. at 592 n.10 (citing Bourjaily v. United States, 483 U.S. 171,

175-76 (1987)).

                                     ANALYSIS

(1)   Dr. Meier’s Expert Testimony

      We first consider the district court’s decision to exclude Dr. Meier’s

testimony under Daubert. Federal Evidence Rule 702 governs the admission of

expert testimony in federal court:

      If scientific, technical, or other specialized knowledge will assist the
      trier of fact to understand the evidence or to determine a fact in issue,
      a witness qualified as an expert by knowledge, skill, experience,
      training, or education, may testify thereto in the form of an opinion or
      otherwise, if (1) the testimony is based upon sufficient facts or data,
      (2) the testimony is the product of reliable principles and methods,
      and (3) the witness has applied the principles and methods reliably to
      the facts of the case.



                                          8
District courts have a duty under Rule 702 to “ensure that any and all scientific

testimony or evidence admitted is not only relevant, but reliable.” Daubert, 509

U.S. at 589.

      The Wilsons first argue that the district court’s application of the Daubert

test to Dr. Meier’s testimony was error. As a treating physician, the Wilsons assert

that Dr. Meier’s testimony regarding his “examinations and diagnosis should not

be subject to an extensive analysis under Daubert or Kumho Tire.”3 Although we

agree that a treating physician may testify as a lay witness regarding his

observations and decisions during treatment of a patient, once the treating

physician expresses an opinion unrelated to treatment which is “based on

scientific, technical, or other specialized knowledge,” that witness is offering

expert testimony for which the court must perform its essential gatekeeping

function as required by Daubert. See United States v. Henderson, 409 F.3d 1293,

1300 (11th Cir. 2005); Leathers v .Pfizer, Inc., 233 F.R.D. 687, 688 (N.D. Ga.

2006).

      In this case, although Dr. Meier was the treating physician, his opinion

regarding the cause of Wilson’s injuries was not needed to explain his decision

making process, nor did it pertain to Wilson’s treatment. See Henderson, 409 F.3d

      3
          Kumho Tire Co. v. Carmichael, 526 U.S. 137 (1999).
                                          9
at 1300 (citing Davoll v. Webb, 194 F.3d 1116, 1138 (10th Cir. 1999) (“A treating

physician is not considered an expert witness if he or she testifies about

observations based on personal knowledge, including the treatment of the

party.”)). Dr. Meier did not need to determine how Wilson was injured in order to

treat him in this case. Testimony regarding his diagnosis of the injury itself - that

Wilson’s spine was fractured - would be permissible as lay testimony without the

Daubert analysis, but his statement about the cause of the injury was an

hypothesis. “And the ability to answer hypothetical questions is the essential

difference between expert and lay witnesses.” Id. (holding that treating physician

provided expert testimony where she expressed an opinion on causation where the

determination of the cause of the injury did not aid in the treatment thereof)

(citations omitted); see also Daubert, 509 U.S. at 592. Dr. Meier’s opinions on

causation, therefore, clearly fall within Federal Rule of Evidence 702’s scope of

“scientific knowledge” and must satisfy Daubert.

      The Wilsons next argue that the district court abused its discretion in

finding that Dr. Meier’s opinion on causation was unreliable. Dr. Meier based his

causation opinion on (1) the fact that Wilson’s injury manifested itself directly

after his exposure to the TASER, (2) conversations with and reports of Drs.




                                          10
Bowerman and Murphy4 in which they stated they believed TASER exposure

could have caused Wilson’s compression fractures, (3) one article reporting a case

in which a patient exposed to TASER developed compression fractures of the

spine,5 and (4) the opinion of Dr. Brown, who conducted an independent medical

examination in another case involving a patient exposed to a TASER device, that

such exposure caused that patient’s spinal compression fractures.6 The Wilsons

claim that Dr. Meier’s reliance on the opinions of his colleagues in forming his

opinion is an accepted medical practice which reliably supports his opinion. They

further argue that although Dr. Meier is admittedly not an expert on the TASER

device, one need not know the mechanics of how a TASER operates to render an



      4
        Although he does not mention Dr. Murphy in his expert report, Dr. Meier
stated at his deposition that he relied upon Dr. Murphy’s opinion and expertise in
reaching his conclusions.
      5
        The district court found that this article was insufficient to provide reliable
support for Dr. Meier’s opinion because the article “contain[ed] only the briefest
of descriptions of the patient’s injury and treatment, and contain[ed] very little
reasoning to support its conclusion that exposure to an electronic weapon may
cause a compression fracture.” On appeal, the Wilsons do not object to this
finding of the district court.
      6
        The district court found that Dr. Brown’s opinion was also insufficient to
support Dr. Meier’s opinion because “the plaintiff in the other case may have had
a very different medical history, physical condition, and course of treatment from
Plaintiff David Wilson.” The Wilsons also do not object to this finding of the
district court.
                                          11
opinion that severe muscle contractions caused by an electric shock can cause

spinal fractures. Finally, they argue that because the injury occurred directly after

the TASER exposure and no other incidents explain the injury, Dr. Meier’s

explanation is the most plausible. Accordingly, they assert that the exclusion of

his opinion testimony on causation was in error.

      In addressing the reliability of expert methodology, “[d]istrict courts ‘have

substantial discretion in deciding how to test an expert’s reliability.’” Rink v.

Cheminova, Inc., 400 F.3d 1286, 1292 (11th Cir. 2005) (quoting United States v.

Majors, 196 F.3d 1206, 1215 (11th Cir. 1999)). In Daubert, the Supreme Court set

out four non-exclusive criteria for reliability determinations: “(1) whether the

expert’s methodology has been tested or is capable of being tested; (2) whether the

technique has been subjected to peer review and publication; (3) the known and

potential error rate of the methodology; and (4) whether the technique has been

generally accepted in the proper scientific community.” McDowell v. Brown, 392

F.3d 1283, 1298 (11th Cir. 2004) (citing Daubert, 509 U.S. at 595). These factors

may guide a district court’s reliability inquiry, but the district court ultimately has

“broad latitude” as to how it determines reliability. Kumho Tire, 526 U.S. at 152.

      We conclude that the district court did not abuse its discretion in excluding

Dr. Meier’s testimony. Simply stated, Dr. Meier does not meet any of the Daubert

                                           12
factors. He did not demonstrate that his opinion that TASER exposure may cause

compression fractures is testable; he did not offer any error rate for his opinion; he

did not show any evidence that his opinion has been peer reviewed or that he used

a peer-reviewed source to reach his opinion; and, finally, he did not show the

general acceptance of his opinion. See Bowers v. Norfolk Southern Corp., 537 F.

Supp. 2d 1343, 1353-54 (M.D. Ga. 2007). Dr. Meier admittedly relied upon his

colleagues’ opinions in reaching his conclusion regarding causation, but, as the

district court properly noted, he offered no basis for his colleagues’ conclusions.

Nothing in the record indicates that Drs. Bowerman or Murphy - any more than

Dr. Meier - relied upon sufficient facts and applied a reliable methodology in

reaching their opinions that Wilson’s injury was caused by TASER exposure.

Accordingly, the district court did not abuse its discretion in finding their opinions

an insufficient basis for Dr. Meier’s causation testimony. Also, during his

deposition, Dr. Meier admitted that “quite osteoporotic patients can have

spontaneous vertebral fractures just from mild movements and falls;” nonetheless,

Dr. Meier did not perform a differential diagnosis or any tests on Wilson to rule

out osteoporosis and these corresponding alternative mechanisms of injury.

Although a medical expert need not rule out every possible alternative in order to

form an opinion on causation, expert opinion testimony is properly excluded as

                                          13
unreliable if the doctor “engaged in very few standard diagnostic techniques by

which doctors normally rule out alternative causes and the doctor offered no good

explanation as to why his or her conclusion remained reliable” or if “the

defendants pointed to some likely cause of the plaintiff’s illness other than the

defendants’ action and [the doctor] offered no reasonable explanation as to why he

or she still believed that the defendants’ actions were a substantial factor in

bringing about that illness.” Wheat v. Sofamor, S.N.C., 46 F. Supp. 2d 1351, 1358

(N.D. Ga. 1999) (citing In re Paoli Railroad Yard PCB Litigation, 35 F.3d 717 (3d

Cir. 1994)).

      Furthermore, although a doctor usually may primarily base his opinion as to

the cause of a plaintiff’s injuries on his history where the plaintiff “has sustained a

common injury in a way that it commonly occurs,” a compression fracture of the

spine is not the type of injury which commonly occurs from a shock by a TASER.

Bowers, 537 F. Supp. 2d at 1354. Accordingly, Dr. Meier could not rely upon the

temporal connection between the two events to support his causation opinion in

this case. See Wheat, 46 F. Supp. 2d at 1359 (excluding testimony where expert

failed to show that any other expert had reached his same conclusion, leaving only

temporal relationship as basis for opinion). Indeed, the complexity of the

causation issue in this case underscores the need for Dr. Meier to have done more

                                          14
than simply adopt Wilson’s history as his causation opinion and opine, without

scientific support, that a TASER could somehow have caused his injury. A

medical degree does not authorize Dr. Meier to testify when he does not base his

methods on valid science. See Flores v. Johnson, 210 F.3d 456, 464 (5th Cir.

2000).

      The trial court has “considerable leeway in deciding in a particular case how

to go about determining whether particular expert testimony is reliable.” Kumho

Tire, 526 U.S. at 152. In this case, applying the Daubert factors, the Wilsons

simply did not prove by a preponderance of the evidence that Dr. Meier employed

a reliable methodology to reach his opinions. For these reasons, we conclude that

the district court did not abuse its discretion in excluding Dr. Meier’s opinions

regarding causation as unreliable and inadmissible.

      (2)    Grant of Summary Judgment

      Because we have concluded that Dr. Meier’s expert testimony was properly

excluded, the only issue remaining before us is whether the district court erred in

granting summary judgment where the record contained no expert medical

testimony on causation.

      Because this action is based on diversity, Georgia substantive standards of

law must apply. Erie R.R. Co. v. Tompkins, 304 U.S. 64, 78 (1938). Under

                                         15
Georgia product liability law, a plaintiff must prove as part of his prima facie case

that the defendant’s product was the proximate cause of the injuries alleged.

Blackston v. Shook & Fletcher Insulation Co., 764 F.2d 1480, 1482 (11th Cir.

1985); Talley v. City Tank Corp., 279 S.E.2d 264, 269 (Ga. Ct. App. 1981). “As a

general rule, issues of causation are for the jury to resolve and should not be

determined by a trial court as a matter of law except in plain and undisputed

cases.” Ogletree v. Navistar Int’l Transp. Corp., 245 Ga.App. 1, 3-4, 535 S.E.2d

545 (2000). In product liability cases, proof of causation generally requires

reliable expert testimony which is “based, at the least, on the determination that

there was a reasonable probability that the negligence caused the injury.”

Rodrigues v. Georgia-Pacific Corp., 661 S.E.2d 141, 143 (Ga. Ct. App. 2008)

(emphasis added); see Maczko v. Employers Mut. Liab. Ins. Co., 157 S.E.2d 44,

46 (Ga. Ct. App. 1967) (“The testimony must show at least a probable cause, as

distinguished from a mere possible cause”). In the alternative, expert testimony

stated only in terms of a “possible” cause may be sufficient if it is supplemented

by probative non-expert testimony on causation. Rodrigues, 661 S.E.2d at 143.

      As discussed above, the inference that a shock by a TASER can and did

cause compression fractures in David Wilson’s spine is not a natural inference that

a juror could make through human experience. See McDaniel v. Employers Mut.

                                         16
Liab. Ins. Co., 121 S.E.2d 801, 804 (Ga. Ct. App. 1961). Therefore, medical

expert testimony is essential to prove causation in this case. Allison v. McGhan

Med. Corp., 184 F.3d 1300 (11th Cir. 1999) (applying Georgia law and finding

that expert medical testimony was essential to prove that silicone breast implants

caused plaintiff’s systemic disease); see also Smith v. Ortho Pharm. Corp., 770 F.

Supp 1561, 1565 (N.D. Ga. 1991) (“Scientific testimony by expert witnesses on

the issue of causation plays an increasingly vital role in [Georgia] products

liability litigation.”). In order to survive summary judgment, the Wilsons must

have presented a competent expert who could testify “to a reasonable degree of

medical certainty” that the TASER caused his injuries, see Allison, 184 F.3d at

1320 (noting standard to which expert must testify), or, in the alternative, they

must have presented medical testimony showing only a possibility of a causal

relation between the TASER exposure and the injury in conjunction with other

evidence, non-expert in nature, indicating that such a relation exists. In the

absence of such expert medical testimony as to probable or possible causation, no

genuine issue of material fact exists on this element of the claim, and the district

court properly granted summary judgment for TASER. See Anderson v. Liberty

Lobby, Inc., 477 U.S. 242, 252 (1986) (explaining that summary judgment is

appropriate if there is a lack of sufficient probative evidence for the plaintiffs’ case

                                          17
because the, “inquiry involved in a ruling on a motion for summary judgment

. . . necessarily implicates the substantive evidentiary standard of proof that would

apply at a trial on the merits”).

      As we discussed above, the only expert medical testimony on causation

proffered by the Wilsons was properly excluded as unreliable. The Wilsons,

therefore, presented no admissible expert testimony about either a probable or

possible causal relation between the TASER exposure and Wilson’s injury.

Accordingly, we conclude that no probative evidence supported a necessary

element of the Wilsons’ failure to warn claim and the district court did not err in

granting summary judgment for TASER on this claim and the other claims

dependant upon that claim.

      AFFIRMED.




                                         18
