Give it a rest :) the guy's emergency wasn't a life crisis - and the guy wasn't ten miles from town at -40 C. 

You had a real deadline. If his car was smoking like crazy I suppose you would have stopped and called CAA for him if his phone was flat. So yeah - read a little Jimmy Carter for therapy - you're doing fine.

I know my old car will boost reliably - and I have boosted when asked - this winter a couple of times by my grown-up daughter - who lives a few km away from me.