A number of arbitrators take the position that a discharge must stand or fall on the facts known to the employer at the time of termination. Many have also held that post-discharge conduct, with the possible exception of conduct of a mitigating nature such as the successful completion of rehabilitation, similarly has no place at the arbitration hearing. To those arbitrators, the question posed in the title is of no importance. However, many arbitrators do take after-acquired evidence and for them the effect, if any, of the Supreme Court's recent decision in McKennon v. Nashville Bannerl is of some significance.
In a 1990 paper delivered at the 43rd Annual Meeting of the National Academy of Arbitrators I suggested that the refusal to accept after-acquired evidence was a limited view stemming, at least it would appear, from a misinterpretation of the conelusions of highly respected arbitrators who came before us and that the failure to consider post-discharge conduct was essentially misguided. Contrary to what some of my colleagues have perhaps unheedingly adopted as a general rule, my research found ample arbitral authority for the consideration and use of after-acquired evidence of pre-discharge misconduct as well as misconduct occurring subsequent to discharge, authority I found highly persuasive.