I think the ultimate is the 1997 case of Liam Donnelly who was fired based on accusations by a student, Rachel Marsden, and put through a year of hell. Only to have it turn out he was innocent, the evidence was fabricated and the person hearing the case was friends with the accuser. And that's only the start. If a local paper, The Province, hadn't kept on the case he would likely never have seen what limited justice he did. The university president resigned over his mishandling - his behavior is a good example of how whipped university administrations had become even then. Rachel Marsden was never punished. Apparently she later tried something similar on a faculty member - but he was a criminologist and fought back. The story of how Donelly was railroaded is mind boggling and worth a read. Start at wikipedia.
Back then the cry wasn't "we believe" it was "why would she lie?" Why indeed. That is a question that needs to asked a lot until false accusations are a thing of the past.