If you analyze it a bit more, you don't find it irrational though?
What would be the motivation of a woman to falsify accusations of someone mentoring her? How often does this actually happen? Wouldn't accusing someone also jeopardize her career prospect? Etc.
I fully understand the response of men not wanting to be alone with women in the workplace, but I can't agree that it's rationale, reasonable and justified. We're all human, and unreasonable feelings of fears and worries is something we all suffer from. That said, the current feelings seem mostly irrational to me, and appear to be put forward by fear mongers.
I am very much in agreement that all are innocent until proven guilty, that the public opinion shouldn't be used as a court of law, and that due process must be followed and respected. That said, I'm still happily mentoring women, and respectfully engaging them at work, and I won't let myself fall prey to these irrational fears.