The 'after-acquired evidence' doctrine precludes or limits an employee from receiving remedies for wrongful discharge if the employer later 'discovers' evidence of wrongdoing that would have led to the employee's termination had the employer known of the misconduct. McKennon v. Nashville Banner Publishing Co., 513 U.S. 352, 360-63, 130 L. Ed. 2d 852, 115 S. Ct. 879 (1995). 'An employer can avoid backpay and other remedies by coming forward with after-acquired evidence of an employee's misconduct, but only if it can prove by a preponderance of the evidence that it would have fired the employee for that misconduct.' O'Day v. McDonnell Douglas Helicopter Co., 79 F.3d 756, 761 (9th Cir. 1996).