Yes. Discrete conduct occurring outside the statute of limitations can be offered as circumstantial evidence of retaliation. For example, if a supervisor threatens to terminate the employment of a whistleblower if the whistleblower raises additional compliance concerns and the supervisor ultimately carries out the threat, the threat itself is relevant to prove retaliation even if it was made outside of the statute of limitations period.
And non-discrete conduct that occurred outside of the statute of limitations can be relied upon to prove retaliation when the earlier conduct only became actionable once other conduct occurring within the limitations period occurred. See Nat’l R.R. Pass. Corp. v. Morgan, 536 U.S. 101 (2002).