The case is Olson v. State of New York, decided on March 17. Claiming disability discrimination, the plaintiff went to trial and lost. He appealed because the jury instruction did not make it clear that the employer is guilty of discrimination even if disability discrimination was not the only reason for plaintiff's termination, so long as disability discrimination was a motivating reason.
This is a legitimate objection. The Court of Appeals notes, "We have consistently held that a plaintiff in an employment discrimination case need not prove that discrimination was the sole motivating factor, the primary motivating factor, or the real motivating factor in the adverse employment action; she need only prove that discrimination was a motivating factor." If you subscribe to the world-view that things happen for many reasons, this theory of liability makes sense. If the employee is fired for 10 reasons, he wins the case if nine reason relate to job performance and one of those reasons was his disability. The idea is that if disability was still a motivating factor, then the employer broke the law.
The Court of Appeals is "troubled" by the trial court's jury instruction which only says that plaintiff has to prove he was fired "because of his disability." This language implies that disability has to be the only reason in order for Olson to win. But there is another line of cases that says that you look at the jury instruction as a whole to see if the trial judge basically gave the jury the correct framework to analyze the case. The Court of Appeals doesn't go there, as it finds instead that the bad instruction was "harmless" in that there was overwhelming evidence that the plaintiff was fired because of his job performance, not because of his disability:
This included, for example, evidence that Olson told his supervisor that "there will be some bloodshed around here," that he repeatedly violated departmental guidelines concerning email usage, that he used inappropriate language to refer to supervisors, and that he drafted a fake memorandum in another officer’s name and circulated it. Significantly, the verdict sheet shows that the jury rejected each alleged claim of discrimination. Moreover, as noted, Olson did not adduce evidence of other employees who engaged in similarly serious misconduct who were not discharged.