An examination of arbitrators’ acceptance (or rejection) of evidence of post-discharge conduct and of later-acquired pre-discharge conduct. Arbitrator Nicolau applies a test of fair warning: If the evidence is revealed when discovered, and in sufficient time for the Union to prepare a defense, the employer is entitled to present it and the arbitrator is obligated to accept and consider it, even if that new evidence does not conform to the original theory of the case. Arbitrator Simons discusses the arbitrator’s remedial authority, and encourages a full make-whole approach and also nontraditional remedies. A right to rehabilitation for addicted employees is discussed, as are concerns about the evidence of post-discharge rehabilitation and reform in substance-abuse cases. Union and Management perspectives are offered.