In an unstable environment take nothing for granted. Even good people do dumb stuff when the very definition of normal is up for grabs. Be shocked, be appalled, be angry, be sad but don't be surprised.
When people feel threatened they will act out of self interest. They quite likely don't realise it so all the more important that you do and make an independent judgment.
Going with the flow can take you a long way from home. Once you lose your bearings the only thing that counts is keeping your head above water, and all possibility for something more meaningful is lost.
If you are in a situation where you cannot behave in a way you feel proud of, you are in a bad situation and should leave.
Don't stay when you know you should go. But don't expect leaving to be painless. Just because its right, doesn't mean its easy.
You can't control what other people do, only try to control your own response.
It doesn't matter how wrong or outrageous someone else's behaviour is, you need to think through the consequences of your own reaction on them - in the end if you paint someone into a corner, they will come out fighting.
Life is too short to always take the safe or easy option. It's also too short to go from one knee jerk to the next.
* these are my rules, and a reminder for me. They are all obvious and trite, but it seems I am nonetheless good at forgetting them. I am making no claim to universal application rule writing status, so no need to tell me I am not a zen master.