You know Johnny Knoxville?

It is rather difficult to see this in a black and white perspective and I agree and disagree depending on the circumstances, the people involved and what exactly had been done. A total act of idiocy from an usual idiot elicits less compassion from me than a singled out act from an otherwise thoughtful person. Sometimes you tell someone to refrain, but they refuse to listen because maybe they think you are wrong, have too much pride to think they are wrong, that there is a chance to escape the negative consequences, just like to take risks, etc. I also see your situation in two parts, one from your friend's side and one from you. I think despite their disregarding your warning and getting in trouble, they still counted on you to extend them a hand because that's what friends and especially family do for each other and it's up to you to decide what kind of person you want to be. My parents will love me no matter what I do or how many times I "don't listen" and vice versa.

I agree. Most people don't or can't think ahead; a skill that we used to teach people.

Helping others is great, but enabling stupidity is actually not doing anyone any good.