One interesting tidbit:
[I]t’s critical to take steps to protect yourself. One way to do that is to have a witness attest to what the liar said. Failing this, interact with the liar via email or text, both of which create a written record.
Though if you’re dealing with a particularly savvy liar, they’re not going to commit to anything in writing. In that case, document the conversation yourself: who, what, when, where, etc., and cap it off by sending your lying colleague an email summarizing the conversation. That’s not as good as having proof in the other person’s words, but at least you’ll be able to make the argument that your colleague had the opportunity to correct you...
