Tuck a voice activated digital recorder amongst your kit and always have it on. Perhaps one of the ones that is also a functional wrist watch and has enough memory to last a shift. I had a situation a few years ago where I went into a company to sort a few problems out. In doing my background research, I realised one of the female middle managers was a serial sexual harassment complainant. Further quiet investigation revealed the complaints were always against male managers who put pressure on her to actually do her job and that her female staff saw her as a vicious bully. Forewarned is forearmed and I took a number of steps. A few months after I started, she requested a meeting about something trivial. It was quite straightforward but there was a certain edgy anticipation on her side. A few hours later I was summoned on to my boss's office where he, the MD and the female manager were waiting. I patiently stood through a harangue from my boss and the MD about my "letting the side down", "this will have to go to a formal complaint unless you're prepared to..." and so on. When they'd talked themselves out, I simply said "you might like to listen to this", pulled out a pen recorder and started playing backing a recording of the meeting. I'd been careful to establish the date and time of the meeting through careful conversation about the day's events, and it was clear I had the whole meeting on tape. I could feel the female manager writhing in her seat just behind me, where a few minutes before she'd been sitting triumphant. All I got from the senior managers was a "yes, well, er, perhaps you've got something to be going on with". Nothing further was said to me about the incident, but the female manager left within a couple of days. As for the senior management, I didn't expect any more from them as I never trusted or relied on them in the first place. (And I had further back up in place, too, but it wasn't needed.) When you're dealing with attention seekers, bullies and liars you have to protect yourself and your colleagues. Few other people will. Look after yourself.