233 F.3d 1036 (7th Cir. 2000)
Mark Mason, Plaintiff-Appellant,v.Southern Illinois University at Carbondale, Defendant-Appellee.
No. 99-3120
In the  United States Court of Appeals  For the Seventh Circuit
Argued February 25, 2000Decided December 5, 2000

Appeal from the United States District Court  for the Southern District of Illinois.  No. 96 C 4135--James L. Foreman, Judge.[Copyrighted Material Omitted][Copyrighted Material Omitted]
Before Bauer, Ripple, and Manion, Circuit Judges.
Manion, Circuit Judge.


1
Mark Mason is a black man  who worked as a dispatcher (or  "telecommunicator") for the Department of Public  Safety (the campus police) at Southern Illinois  University (SIU). His health problems frequently  caused him to miss work for substantial periods  of time, and these absences either caused or  greatly contributed to his supervisor's dislike  of him. Mason thought this dislike was racially  motivated, so after he was fired, he sued SIU  under Title VII. A jury found for SIU, and Mason  appeals, contending that the district court erred  in excluding evidence of racial epithets that  some of his coworkers allegedly made when neither  he nor his supervisor were around. Because the  district court did not abuse its discretion, we  affirm.

I.  Background

2
Mark Mason worked as a dispatcher at SIU from  1983-1998. His health-related absences from work  (which had always been considerable) increased  substantially after 1991 when Corporal Carol  Kammerer, a white woman, became his supervisor.  One absence lasted nine months, from September,  1994 to May, 1995. When Mason returned to SIU, he  worked for about six weeks, took extended sick  leave again in July, 1995, and never returned to  work. While on his latest leave, Mason filed a  worker's compensation claim against SIU for  stress; he also unsuccessfully sought other  employment with SIU. Mason settled this claim in  the summer of 1998. As part of the settlement,  SIU offered him his job back, but Mason refused  this offer. Under the civil service rules, SIU  had two options at this point--Mason could resign  or be terminated. Mason refused to resign, so he  was fired.


3
According to Mason, his refusal to return to  work was due to the rocky relationship he had  with Kammerer. He claimed she was abusive toward  him, such as by allegedly calling him "stupid"  and "dumb" when he would incorrectly perform a  task. (Kammerer denies referring to Mason ever in  this fashion.) Even though Kammerer never made  racist remarks in Mason's presence, let alone to  him, Mason believed Kammerer treated him badly  because he was black and that this treatment  exacerbated his health problems, which ultimately  prevented him from working for her. He sued SIU  under Title VII, claiming racial discrimination  in the form of a hostile work environment. The  case proceeded to trial, where the district court  excluded racial epithets allegedly made by  Mason's coworkers which neither Mason nor  Kammerer ever heard. Mason lost his case before a  jury and appeals the district court's evidentiary  ruling, asking for a new trial. Mason now claims  that not only his supervisor but also his  coworkers created the allegedly hostile work  environment. Because there is a distinction in  the legal analysis, we first need to resolve this  dispute.

A.  Mason's Title VII Claim

4
A close examination of Mason's complaint  discloses that he alleged only that his  supervisor, not his coworkers, was racially  harassing him. The relevant paragraphs of the  complaint are as follows:


5
21. During the course of his employment with the  Defendant, the Plaintiff was subjected to  unwelcome harassment by his supervisor,  including:


6
a. Exposure to stress and harassment


7
b. Exposure to racial epithets


8
c. Being passed over for promotions and overtime.


9
* * *


10
24. That the actions of the Plaintiff's supervisor  were performed as an agent of the Defendant  herein and in the course of the supervisor's  duties as supervisor.


11
(Emphasis added.) Mason never amended this  complaint to include a claim for coworker-created  hostile work environment. Nor did he otherwise  notify SIU that he was complaining of anything  other than a supervisor-created hostile work  environment.1


12
Even at trial Mason continued to insist that  Kammerer was the source of his problems. He  stated that in 1992 he met with the then-newly  hired head of the Public Safety Department, Sam  Jordan, to complain that Kammerer was being  "racist towards me" by "calling me dumb and  stupid and aggravating me." He later complained  to Jordan that he had been having "an ongoing  problem" with Kammerer "harassing me, and I felt  that she was constantly picking on me because I'm  black." After years of working underneath  Kammerer, Mason testified that his health began  to deteriorate. He felt that working for her "was  aggravating, humiliating. It was hostile, and I  wanted to get [out] from under her." He stated  that while he had experienced some health  problems before working for Kammerer, his  symptoms increased substantially once she became  his supervisor. Mason stated that he had talked  with "Jordan many times because it appeared to be  a constant problem that I was having with  Kammerer." As a result, Mason talked with Jordan  about getting another job in the department, and  he made other efforts "to try to get away from  Corporal Kammerer's supervision." Mason went on  disability leave in late 1994 because Kammerer's  behavior was harming his health:


13
[W]orking at the Department of Public Safety--  excuse me--working at the Department of Public  Safety under Corporal Carol Kammerer was causing  too much problems on my health and no--the  university wasn't taking no [sic] actions to  correct the situation.


14
(Emphasis added.) He told the jury that after he  "had been out of the work environment under  Carol--under Corporal Kammerer for several  months," his "condition started to improve." He  then briefly mentioned that when he returned to  work in May of 1995, his white coworkers "acted  isolated towards me," not talking "to me like  they generally did. Sometimes I would speak to  them and they wouldn't even speak back to me."  Mason said that when he returned to work for the  last time, Kammerer "started treating me the way  she normally treated me. Yell at me, scream at  me, holler at me. [sic]" According to him, as of  the trial, Kammerer was still "in charge of  telecommunicators" and he was not "aware of any  action that's been taken against her" in response  to his complaints about her.


15
On cross-examination, Mason confirmed that his  harassment claim was based on Kammerer's conduct,  not that of his coworkers or anyone else:


16
Q. And you were offered the position you were  offered your position to return to once you had  completed [maximum medical improvement as part of  Mason's workman's compensation claim]?


17
A. That's correct.


18
Q. And you said you weren't going to return to the  telecommunicator's job at SIU; is that right?


19
A. No. I said I do not want to return back to work  that position working under Corporal Carol  Kammerer.


20
Q. Oh. You would have worked in the radio room,  but just under another supervisor?


21
A. If they would have allowed me.


22
Q. So it wasn't the radio room? It was Kammerer?


23
A. Yes.


24
(Emphasis added.) Mason twice repeated that  Kammerer was the cause of his problems.2


25
The focus of this testimony regarding  mistreatment by his supervisor is important  because a probationary dispatcher named Patty  Shands worked in the telecommunications division  for about five months during the spring and  summer of 1995. She became friends with Mason and  was called to testify on his behalf regarding her  observations of the conduct of Kammerer and other  employees in the division. A key issue at trial  and on appeal is the extent to which the judge  limited her testimony.


26
B.  Shands' Testimony and Mason's Offer of Proof


27
After he testified, Mason called Carol Kammerer  to the stand who, not surprisingly, denied  calling Mason "dumb" or "stupid" or using a  racial epithet to refer to him or any employee.  She denied ever hearing a subordinate make a  racially derogatory remark, and stated that she  would not allow a subordinate to make such a  remark. Mason attempted to ask Kammerer whether  she knew that Patty Shands had alleged that a  white dispatcher had "used the word 'n' word." At  this point, SIU moved to bar Shands' testimony  concerning actions by coworkers, arguing that it  was not relevant to the claim of supervisor-based  harassment that Mason had consistently alleged in  his pretrial filings and had just laid out in his  own testimony. The district court concluded that  Mason was making a claim of a racially hostile  work environment caused by his supervisor, Carol  Kammerer. As a result, it would allow Shands to  testify to anything she heard Kammerer say. And  in order to allow Mason to show that Kammerer, as  the racial harasser, was responsible for creating  the work environment in general, the district  court would also allow Shands to testify to  anything that coworkers said in Kammerer's  presence (although the court thought even this  might be crossing the line into irrelevant  testimony). In other words, while Mason's claim  was predicated on Kammerer's behavior, the court  would allow Mason to develop a theory in which  her behavior extended to approving the alleged  racist conduct of subordinates.


28
Shands took the stand and testified that once  when Kammerer was upset because Mason's health-  related absence forced her to re-do the work  schedule, Kammerer referred to Mason as Jordan's  "token nigger" in front of Shands and two  coworkers. Shands' testimony then violated the  court's order when she stated that after Kammerer  left the room, one of her two coworkers referred  to Mason in the same way. SIU objected, and the  district court instructed the jury to disregard  this piece of testimony. Shands again went beyond  the court's ruling by stating that before  Kammerer allegedly referred to Mason in that  derogatory manner, Shands had never heard any of  her coworkers refer to him that way. Then she  testified about another time when Kammerer was  upset at having to alter the work schedule and a  coworker allegedly referred to Mason as a "token  nigger" in front of Kammerer; Kammerer did not  react to (let alone discipline) the coworker for  doing so. Finally, Shands testified that after  she became friends with Mason, her coworkers  "blackballed" her. She also noted that after she  was fired from the communications division in  July, she filed a complaint with SIU discussing  "racial issues" in the Department of Public  Safety, and she subsequently filed a charge with  the EEOC claiming that she was fired because she  was friends with Mason.


29
Mason's counsel made an offer of proof as to  what Shands' testimony would have included had  the court not restricted her. He said that Shands  would have testified that her coworkers: 1) used  racial epithets to refer to black people  generally or to Mr. Mason in particular, and one  coworker called her a "nigger-lover"; 2) told her  "not to even mention Mark Mason's name in front  of Corporal Kammerer" and that "if she did she  would have to look for another job"; 3) told her  that "Kammerer hates Mark Mason," was "sick of  him and doesn't like having to work with him";  and 4) increased their usage of racial epithets  dramatically after Kammerer used a racial epithet  to refer to Mason. The district court had  excluded the proposed testimony because it would  be confusing to the jury and prejudicial; the  court was trying "a lawsuit involving Mark Mason  and SIU, and then we jump the track and we start  trying Patty Shands' case." It also thought the  proposed testimony would be irrelevant: Mason's  claim concerned a "hostile work environment  brought about by a supervisor, and all the  testimony that you were wanting to bring out and  have made the offer of proof on does not  necessarily tie itself to Ms. Kammerer who is the  supervisor involved." And the court considered  the testimony to be cumulative because there was  already substantial evidence showing Kammerer's  hostility. Finally, the court seemed to question  whether Shands' testimony would be perjurious.  She had executed an affidavit stating that she  never heard anyone in the Department of Public  Safety use a racial term and that she never heard  anyone in the Department use such a term about  Mason.3 The jury returned a verdict for SIU.  Mason now challenges the district court's  evidentiary ruling that limited Shands'  testimony.

II.  Discussion

30
We review the district court's decision to  exclude testimony for an abuse of discretion.  Palmquist v. Selvik, 111 F.3d 1332, 1339 (7th  Cir. 1997). An "appellant carries a heavy burden  in challenging a trial court's evidentiary  rulings" because of the "special deference" a  reviewing court gives them. Id. Furthermore, even  if Mason meets this heavy burden, we do not  reverse a jury verdict if the error is harmless;  the error must have affected the party's  substantial rights. See Fed. R. Civ. P. 61  (disregard errors that do not affect "substantial  rights"); Fed. R. Evid. 103(a) (error must affect  "a substantial right of a party"); Jones v.  Lincoln Elec. Co., 188 F.3d 709, 725 (7th Cir.  1999) (citing Fed. R. Civ. P. 61 and Fed. R.  Evid. 103) (reversal is required and a new trial  is warranted only if error affected a party's  substantial rights). The party must also have  made the substance of the evidence known to the  court by an offer of proof or otherwise. Fed. R.  Evid. 103(a); United States v. Cleggett, 179 F.3d  1051, 1055 (7th Cir. 1999). The offer of proof  (or the record elsewhere) must show "the grounds  for admissibility, what the proponent expects to  prove by the excluded evidence, and the  significance of the excluded testimony."  Cleggett, 179 F.3d at 1055; see also United  States v. Vest, 116 F.3d 1179, 1189 (7th Cir.  1997).


31
The law against discrimination in the workplace  is well settled. Title VII provides that it  "shall be an unlawful employment practice for an  employer . . . to fail or refuse to hire or to  discharge any individual, or otherwise to  discriminate against any individual with respect  to his compensation, terms, conditions, or  privileges of employment, because of such  individual's race . . . ." 42 U.S.C. sec. 2000e-  2(a)(1). An employer may be liable for  discrimination within the meaning of Title VII if  an employee is subject to a hostile work  environment based on his race. To recover, an  employee must show that: 1) he was subject to  unwelcome harassment; 2) the harassment was based  on his race; 3) the harassment was severe and  pervasive so as to alter the conditions of the  employee's environment and create a hostile or  abusive working environment; and 4) there is a  basis for employer liability. See Parkins v.  Civil Constructors of Ill., Inc., 163 F.3d 1027,  1032 (7th Cir. 1998). The employer is essentially  strictly liable if the employee's supervisor  created the hostile work environment. See  Burlington Indus., Inc. v. Ellerth, 118 S. Ct.  2257, 2270 (1998); Faragher v. City of Boca  Raton, 118 S. Ct. 2275, 2292-93 (1998).4 The  employer is liable for a hostile work environment  created by the employee's coworkers, however,  only when the employee shows that his employer  has "been negligent either in discovering or  remedying the harassment." Parkins, 163 F.3d at  1032.

A.  Mason's Claim

32
In his reply brief, perhaps recognizing the  problems with using coworker conduct to prove a  claim of supervisor harassment, Mason contends  that he properly presented a claim based on  coworker harassment in the first place, in  addition to his claim based on supervisor  harassment. If so, he now contends that Shands'  excluded testimony is relevant to proving the  coworker aspect of his claim. The district  court's accurate conclusion that Mason only  presented a claim for supervisor harassment was  clearly critical to its evidentiary ruling.  Because Mason does not dispute this conclusion  until his reply brief, this new argument is  waived. See Holman v. Indiana, 211 F.3d 399, 405  n. 5 (7th Cir. 2000).


33
Assuming this argument were preserved, it is of  course true, as Mason notes, that Fed. R. Civ. P.  8(a) only requires a short and plain statement  that will provide the defendant with fair notice  of his claim. See Ryan v. Mary Immaculate Queen  Ctr., 188 F.3d 857, 860 (7th Cir. 1999). But as  we have noted, Mason's complaint does not fairly  notify SIU that he is claiming coworker  harassment. Although he attempts to magnify the  meaning of paragraph twenty-three of his  complaint,5 it is not only silent on coworker  conduct, but it is inextricably sandwiched  between two paragraphs specifically discussing  supervisor harassment. Mason might have been able  to shoehorn a claim for coworker harassment into  paragraph twenty-three for purposes of surviving  a motion to dismiss by alleging hypothetical  facts about harassing coworkers. But even then  the hypotheticals would have to be consistent  with his allegations of supervisor harassment.  See Holman, 211 F.3d at 405. Aside from the fact  that he has produced no evidence of his being  harassed by coworkers, Mason has consistently  represented that he was claiming supervisor  harassment. He did so during discovery, and he  repeatedly testified at trial that this was  indeed his claim. His one brief comment  concerning his coworkers-- that while they  "generally" talked to him, after he returned from  his nine-month absence "sometimes" they wouldn't-  -is hardly sufficient, given the overwhelming  thrust of his testimony, to place SIU on notice  that he was (now) claiming an additional type of  hostile work environment. Certainly by the time a  plaintiff testifies in his case in chief, a  defendant is entitled to rely on the notice that  the complaint has given him when its allegations  are confirmed by the plaintiff's own trial  testimony. See Vidimos, Inc. v. Laser Lab Ltd.,  99 F.3d 217, 222 (7th Cir. 1996). To allow Mason  to introduce evidence of alleged coworker  harassment via Shands' testimony would be  allowing him to amend his complaint to include a  new claim based on coworker harassment. See  Chaveriat v. Williams Pipe Line Co., 11 F.3d  1420, 1428-30 (7th Cir. 1993). At this late stage  of the case, the district court did not abuse its  discretion in not allowing Mason to do so. Id. at  1430 (court does not abuse its discretion when it  prevents unfair prejudice to defendant from  admitting evidence that would inject a new claim  late in the proceedings).6


34
B.  Analyzing the Totality of  Circumstances


35
As shown above, this case involves allegations  of harassment by a supervisor. Yet in his initial  appellate brief, Mason essentially argues that  all evidence of harassment is always relevant,  regardless of the type of claim the plaintiff is  asserting, and that therefore all of Shands'  testimony was relevant and admissible. This broad  assertion is not correct.


36
Harassment "by co-workers differs from  harassment by supervisors." Parkins, 163 F.3d at  1032. As a result, an "employer's liability for  hostile environment sexual harassment depends  upon whether the harasser is the victim's  supervisor or merely a co-employee." Id. This  same distinction applies in a racial harassment  case when determining employer liability.


37
If a plaintiff claims that he is suffering a  hostile work environment based on the conduct of  coworkers and supervisors, then under the Supreme  Court's totality of circumstances approach,  Farragher, 118 S. Ct. at 2283 (citing Harris v.  Forklift Systems, Inc., 510 U.S. 17, 23 (1993)),  all instances of harassment by all parties are  relevant to proving that his environment is  sufficiently severe or pervasive. See Williams v.  General Motors Corp., 187 F.3d 553, 559, 562-63 &  n.4 (6th Cir. 1999) (plaintiff's claim was based  on the behavior of supervisors and coworkers and  conduct of both types of harassers was relevant);  Silk v. City of Chicago, 194 F.3d 788, 803, 806  (7th Cir. 1999) (assuming there is an ADA hostile  work environment claim, actions of both coworkers  and superiors are relevant to determining whether  environment was severe or pervasive). Courts  should not carve up the incidents of harassment  and then separately analyze each incident, by  itself, to see if each rises to the level of  being severe or pervasive. Williams, 187 F.3d at  561-62.


38
That does not mean, however, that courts can  automatically lump into the analysis of the  behavior by one type of harasser behavior by a  different type of harasser when the plaintiff is  not pursuing a claim based on the latter's  conduct. Cf. id. at 562 ("District courts are  required to separate conduct by a supervisor from  conduct by co-workers in order to apply the  appropriate standards for employer liability.");  Parkins, 163 F.3d at 1032 (liability depends on  whether harassment is by supervisor or  coworkers). If a plaintiff pursues a hostile work  environment claim based on the behavior of a  supervisor, evidence of harassment by a coworker  logically must be tied somehow to the supervisor  for it to be relevant and admissible. Otherwise,  including such evidence could confuse the jury  and prejudice the defendant. See Fed. R. Evid.  403.7 Thus, when considering the totality of  the circumstances the district court here did not  abuse its discretion when it limited Shands'  testimony to behavior and comments attributed to  Kammerer, or to those attributed to coworkers  while Kammerer was present.


39
C. Supervisor Harassment and Shands' Excluded  Testimony


40
Mason also argues that Shands' excluded  testimony is relevant to his claim of a  supervisor-created hostile work environment to  show the pervasiveness of the environment or to  show Kammerer's "real" motives for her ostensibly  "race-neutral" treatment of him. In some  "supervisor" cases, evidence of coworker behavior  might be relevant to show pervasiveness or  motive. But Mason did not make these arguments  until his reply brief, so they are waived. And  even if he had preserved them, in this case, as  we shall see, these arguments are re-packaged  attempts to use incidents of coworker behavior to  establish a claim that is based on supervisor  harassment. Furthermore, neither Mason nor  Kammerer were even present for the alleged  incidents of coworker harassment that Shands'  testimony would purportedly expose. Thus, Mason  is trying to hold SIU strictly liable (by  nominally proceeding under a claim of supervisor  harassment) by using evidence of coworker  harassment of which neither he nor the supervisor  in question were even aware. Mason cannot  bootstrap coworker behavior onto his claim of  supervisor harassment.


41
As to pervasiveness, Mason argued to the  district court that the conduct of his coworkers  is relevant to some sort of derivative supervisor  harassment theory under which Kammerer, through  racist behavior, "sets the tone" of the  department, signaling to subordinates that it is  okay if they harass Mason, their coworker. Cf.  Knox v. Indiana, 93 F.3d 1327, 1334 (7th Cir.  1996) (noting possibility of a Title VII  retaliation theory where a supervisor permits a  plaintiff's "fellow employees to punish her for  invoking her rights under Title VII"). As we  understand Mason's theory of "supervisor"  harassment, the actions of the coworkers are  deemed to be the actions of the supervisor for  which the company is then (strictly) liable. This  appears to be another "bootstrapping" effort, but  since Mason has failed to pursue this argument on  appeal, we need not wrestle with it.


42
Whatever supervisor-based theory Mason might  wish to employ to establish pervasiveness, there  is a clear problem with using Shands' excluded  evidence of coworker comments: Mason never knew  of these comments. Mean-spirited or derogatory  behavior of which a plaintiff is unaware, and  thus never experiences, is not "harassment" of  the plaintiff (severe, pervasive, or other).  Thus, for alleged incidents of racism to be  relevant to showing the severity or pervasiveness  of the plaintiff's hostile work environment, the  plaintiff must know of them. See Ngeunjuntr v.  Metropolitan Life Ins. Co., 146 F.3d 464, 467  (7th Cir. 1998) (racial comments made outside  employee's presence did not show hostile  environment); Johnson v. City of Fort Wayne, 91  F.3d 922, 938 & n.8 (7th Cir. 1996) (harassing  conduct must be directed at employee in order to  show racially hostile environment); see also  Burnett v. Tyco Corp., 203 F.3d 980, 981 (6th  Cir. 2000) (hostile actions of which plaintiff  was unaware were not relevant to her claim of a  hostile work environment); Carter v. Chrysler  Corp., 173 F.3d 693, 701 n.7 (8th Cir. 1999)  (Plaintiff knew of graffiti "during the time in  which she experienced harassment. It is thus  relevant on whether a hostile work environment  existed . . . ."); cf. Hardin v. S.C. Johnson &  Son, Inc., 167 F.3d 340, 347 (7th Cir. 1999)  (doubting the admissibility "of odious  statements" plaintiff never heard to show racial  motive).8


43
Here, it is undisputed that no one ever made  such comments to Mason or in his presence, and in  his offer of proof, Mason's attorney did not  advise the court that Shands would testify that  she had ever told Mason about his coworkers'  alleged use of racial epithets. Nor is it  otherwise apparent from the record that Shands  told Mason about them (or that he otherwise knew  of them).9 Mason's offer of proof thus failed  to advise the district court of how Shands'  testimony would be of significance in terms of  establishing pervasiveness. United States v.  Peak, 856 F.2d 825, 832 (7th Cir. 1988) ("the  adequacy of [an offer of proof] is an essential  prerequisite to a finding of error").


44
As we have said, "it is up to the party  challenging exclusion to formulate an offer which  satisfies all needs. One of the needs in this  case was some indication" that, at a minimum,  Mason was aware of these epithets. United States  ex rel. Veal v. DeRobertis, 693 F.2d 642, 648  (7th Cir. 1982); see also United States v. King,  75 F.3d 1217, 1223 (7th Cir. 1996) (requiring  specificity in offer of proof and rejecting  "blanket" offers). Mason acknowledged at oral  argument that his "counsel had an opportunity to  make a full and complete offer of proof." United  States v. Schroeder, 902 F.2d 1469, 1471 (10th  Cir. 1990). There is no reason why he could not  have offered to have Shands prove that she told  Mason about the racial epithets his coworkers  allegedly used when he wasn't around. Because we  do not know whether Shands was in fact prepared  to so testify, we cannot assess whether the  exclusion was "prejudiciously erroneous." See  Cleggett, 179 F.3d at 1055; King, 75 F.3d at  1223; United States v. Alden, 476 F.2d 378, 381  (7th Cir. 1973).


45
Mason also argues that the excluded evidence of  coworker comments is relevant to show that  Kammerer's racially neutral but negative  treatment of him was based on his race. See  Carter, 173 F.3d at 701. More specifically, it  would show that Kammerer did not put a stop to  Mason's coworkers' alleged racist comments  because of her own racial animus. We disagree  with the relevance of such evidence here. The  district court allowed into evidence anything  racial that Kammerer allegedly said (even when  Mason was not around), as well as anything racial  that coworkers allegedly said in Kammerer's  presence (again, even when Mason was not there).  What Mason seeks to admit to establish Kammerer's  motives are statements that coworkers allegedly  made when she was not there. While evidence of  coworker behavior of which the supervisor was  aware might be relevant to show the supervisor's  motives, Carter, supra, there has to be proof  that she was aware of or that she at least had  some connection to the behavior. Because Kammerer  was not present on those occasions when coworkers  allegedly made the comments in question, the  alleged comments are not relevant to showing her  motives. Cf. Hunt v. City of Markham, Ill., 219  F.3d 649, 652 (7th Cir. 2000) ("the fact that  someone who is not involved in the employment  decision of which the plaintiff complains  expressed discriminatory feelings is not evidence  that the decision[maker] had a discriminatory  motivation"); Smith v. Leggett Wire Co., 220 F.3d  752, 759 (6th Cir. 2000). Therefore, the district  court did not abuse its discretion in excluding  this evidence.

D.  Harmless Error

46
Assuming it was error to exclude this testimony,  the exclusion did not deprive Mason of a  "substantial right" (as required by Fed. R. Civ.  P. 61 and Fed. R. Evid. 103(a)) in that we do not  think the outcome would have been different but  for the excluded testimony. Jones, 188 F.3d at  725. If Shands had attempted to testify that when  neither Kammerer nor Mason were around her  coworkers sometimes used racial epithets, SIU  would have attempted to impeach her with her  affidavit in which she swore unequivocally that  at no time did she ever hear any racial epithets  at SIU, including ones referring to Mason. As it  stood, the jury heard Patty Shands' accounts of  racial epithets in the Public Safety Department;  it simply did not believe her. We doubt her  credibility with the jury would have improved  much once SIU cross-examined her with her  unequivocally contrary affidavit.


47
Shands' remaining testimony was about coworkers'  statements that Kammerer disliked Mason. Mason  testified to this at great length. Thus, to say  that this testimony would be cumulative is an  understatement. The jury was already left with  this impression; it just didn't believe that  racial prejudice caused it. It is unlikely that  excluding such cumulative evidence would have  caused the jury to find differently. Palmquist,  111 F.3d at 1341 (harmless error to exclude  cumulative evidence); cf. Bankcard America, Inc.  v. Universal Bancard Systems, Inc., 203 F.3d 477,  482 (7th Cir. 2000) (not plain error to admit  cumulative evidence).

III.  Conclusion

48
The district court did not abuse its discretion  in not allowing Mason effectively to amend his  complaint during the trial to present an  additional claim for racial harassment based on  the actions of his coworkers. Furthermore, given  that Mason presented a claim for harassment based  on the conduct of his supervisor, the district  court did not abuse its discretion in not  admitting evidence of comments that coworkers  allegedly made when neither Mason nor his  supervisor were present. Finally, even had the  court abused its discretion in excluding this  evidence, the error would have been harmless.


49
For the foregoing reasons, then, the judgment of  the district court in favor of the defendant is AFFIRMED.



Notes:


1
 For example, in his brief in support of his  motion to compel, Mason stated that he was  claiming that Kammerer was subjecting him to a  hostile work environment. See Plaintiff's  Memorandum Supporting His Motion To Compel  Defendant To Produce Documents at 1 ("Plaintiff  alleges that Kammerer repeatedly made racially  harassing comments to him and about him, harassed  him because of his race, and discriminated  against him because of his race."); id. at 4  ("[T]he documents would be crucial for plaintiff  to be able to prove that Kammerer harassed him  because of his race."). As a result, the district  court viewed Mason as claiming a supervisor-  created hostile work environment. See Memorandum  And Order (Plaintiff's Motion to Compel) at 1-2  ("Mason alleges that Kammerer repeatedly made  racially harassing comments to him and about him  and otherwise harassed and discriminated against  him because of his race."); id. at 2 ("Mason has  sued under Title VII . . . alleging that . . .  Carol Kammerer racially harassed him and made  racially derogatory comments to and about him.").


2
 For example, Mason testified that:
A. I believe I said [in writing to SIU's Director  of Human Resources] I would like to go back to  work, but I did not want to go back to work under  Carol Kammerer. . . . I was expressing the fact  that I wanted to work. I didn't want to be off  work, but I didn't want to have to work under  Carol Kammerer and [sic] aggravated, harassed,  treated unfair--. . . . Being unfair and her  being racist towards me.
Q. So if Lieutenant Doan had taken over  responsibilities for supervising the radio room,  that would have been fine?
A. Sure. That would have been fine. The job was  not the problem. Corporal Kammerer was the  problem with me.
(Emphasis added.)


3
 Specifically, Shands swore in the following  paragraphs of her affidavit that:
4. At no time during my employment in the  Department of Public Safety at Southern Illinois  University did I personally hear any police  officer or supervisor in the Department of Public  Safety make any racially derogatory remark.
5. At no time during my employment in the  Department of Public Safety at Southern Illinois  University did I personally hear any police  officer or supervisor in the Department of Public  Safety make any racist remark concerning Mark  Mason.


4
 If the employee does not suffer a "tangible  employment action" as a result of such  harassment, the employer may raise an affirmative  defense comprising two elements: "(a) that the  employer exercised reasonable care to prevent and  correct promptly [the] harassing behavior, and  (b) that the plaintiff employee unreasonably  failed to take advantage of any preventive or  corrective opportunities provided by the employer  or to avoid harm otherwise." Ellerth, 118 S. Ct.  at 2270; Farragher, 118 S. Ct. at 2293. Here, SIU  has not raised the affirmative defense, and it is  thus waived.


5
 "That the harassment had the effect of  unreasonably interfering with Plaintiff's work  performance, and creating an intimidating,  hostile and offensive work environment that  seriously affected the psychological well-being  of the Plaintiff." Complaint, para. 23.


6
 Mason argues that SIU "was fully aware of  plaintiff's claim of coworker harassment" because  it did not object to a proposed jury instruction  regarding coworker harassment that Mason had  drafted and that the parties had submitted as  part of their joint instructions. This contention  was also not raised until Mason's reply brief,  and to the extent he is contending that this  submission implies SIU's agreement under Fed. R.  Civ. P. 15(b) to amending the pleadings, we  disagree. See Rosario v. Livaditis, 963 F.2d  1013, 1022 n.4 (7th Cir. 1992). SIU's repeated  objections to Shands' proposed testimony as not  relevant to Mason's claim of supervisor  harassment belie any notion that SIU tacitly  consented to Mason bringing in at trial an  additional claim based on coworker harassment.  Contrast Whitaker v. T. J. Snow Co., 151 F.3d  661, 663 (7th Cir. 1998) ("Because both parties  squarely addressed the strict liability theory in  their summary judgment briefs, the complaint was  constructively amended to include that claim.").


7
 While in Williams, upon which Mason relies, the  Sixth Circuit recognized that courts must  separate supervisor and coworker conduct "in  order to apply the appropriate standards for  employer liability," id., it stated that it is  not appropriate to separate the conduct according  to the type of perpetrator to determine whether  the harassment is severe or pervasive. See 187  F.3d at 562 & 563 n.4. Williams is  distinguishable from this case in that the  plaintiff there was claiming a hostile work  environment based on the actions of both  supervisors and coworkers, see id. at 559,  whereas Mason has pursued only a supervisor-based  hostile work environment claim.


8
 We have stated, however, that with respect to a  hostile work environment claim that is predicated  on coworker behavior, the pervasiveness of  coworker conduct could show the employer's  constructive notice of the harassment (presumably  even if the plaintiff is not present). Wilson v.  Chrysler Corp., 172 F.3d 500, 509 (7th Cir.  1999).


9
 The only indication in the record that Mason and  Shands might have discussed their coworkers'  alleged comments is Mason's one-word mention  during his testimony that he and Shands had  talked about "discrimination." But this solitary  reference is too cryptic to have apprised the  district court (or us) that Shands indeed told  Mason of these statements. And even if Shands  told Mason about some of these comments, such  "through the grapevine" or "second-hand" conduct  is not sufficiently severe or pervasive so as to  create a hostile work environment. See Savino v.  C.P. Hall Co., 199 F.3d 925, 933 (7th Cir. 1999);  Adusumilli v. City of Chicago, 164 F.3d 353, 362  (7th Cir. 1998). And if we further assume that  Shands did relay these incidents to Mason, we do  not know how many times she did so; an isolated  (and in this case second-hand) comment also does  not create a severe or pervasive environment. See  Farragher, 118 S. Ct. at 2283-84 ("offhand  comments . . . will not amount to discriminatory  changes in the 'terms and conditions' of  employment'"); see also Ngeunjuntr, 146 F.3d at  467 (isolated racial comments did not show a  severe or pervasive environment).



50
RIPPLE, Circuit Judge, concurring.


51
In this case,  an employee seeks to establish a case of racial  harassment at the hands of a supervisor. In order  to prove his case before a jury, the employee  sought to establish that the supervisor made  racially derogatory remarks about him before  other employees and that, as a consequence of  these remarks, there was a perceptible change in  the manner in which his coworkers treated him.  The district court admitted all behavior and  statements of the supervisor and all behavior and  statements of the coworkers when the supervisor  was present. It refused to admit, however,  behavior and statements of the coworkers when the  supervisor was not present.


52
It is important to note what the court does not  decide. The court does not decide that, as a  general principle, statements made by coworkers,  when the supervisor is not present, are  inadmissible to prove supervisor harassment of a  worker in violation of Title VII. The court  recognizes that such coworker statements may be  relevant in assessing the conduct of the  supervisor when the circumstances support the  inference that there is a causal relationship  between the supervisor's statements and the  behavior or statements of the coworkers. In  acknowledging the relevance of such evidence, the  court is recognizing the practical realities of  the workplace. A supervisor ought not escape the  strictures of Title VII when she sets the stage  for the harassment of a worker and then simply  absents herself when the actual harassment takes  place.


53
As my colleagues note, in proving supervisor  harassment, evidence of coworker behavior can be  relevant to establish the motive of the  supervisor. In order to establish the necessary  link to the supervisor, however, it is necessary  to show, by direct or circumstantial evidence,  that the supervisor was aware, or should have  been aware, that her actions or words would lead  to the behavior and words of the coworkers. To  establish a supervisor's motive through the words  and actions of the coworkers, it is necessary to  show that the supervisor should have realized  that her activity would lead to such a result.  Here, the employee wished to show that, after the  supervisor made racially derogatory comments in  the presence of coworkers, there was a  substantial increase in racial epithets in the  coworkers' parlance and that he was isolated by  those workers in the daily activities of the  workplace. My colleagues believe that the  district court was on solid ground in declining  to admit the evidence of the coworker's statement  because there is no evidence that the supervisor  was present when the statements were made. It is  not clear, however, why the supervisor's presence  is necessary to establish the relevance of the  statements to the issue of the supervisor's  intent. The defense wanted to establish that, in  making racially charged statements in front of  the coworkers, the supervisor was sending a  signal that treating the plaintiff in a racially  discriminatory matter was acceptable conduct in  which the workers could indulge safely without  fear of reprisal--a message confirmed when a  coworker did make such a statement before the  supervisor and incurred no sanction.


54
The actions and statements of the coworkers also  can be relevant, as my colleagues also  acknowledge, on the issue of whether the  harassment was pervasive. Here again, the  employee was entitled to show that the  supervisor's statements to the coworkers signaled  that the supervisor condoned, or even encouraged,  the racial harassment of the employee.


55
My colleagues suggest, however, that the remarks  of the coworkers are irrelevant on both the  intent issue and on the pervasiveness issue  because the employee never knew of the comments.  The majority is certainly correct in stating that  mean-spirited or derogatory behavior of which the  plaintiff is unaware and therefore never  experiences are not, in themselves, "harassment."  But, even if these statements were not, in  themselves, instances of harassment, their  occurrence can certainly be relevant for the  limited purposes of showing the intent of the  supervisor in making the statements and to  demonstrate that the statements that were heard  by the employee were the products of an intense  and concerted effort to set the employee apart  from his fellow workers on the basis of his race.


56
Although the tendered evidence was relevant, the  decision of the district court not to admit it in  this case must be sustained. For the reasons  given by my colleagues, the failure to admit this  material must be considered harmless error.


57
On this basis, I join the judgment of the court.

