I agree - I'd definitely make an issue of it. At my DD's kindy they have it written in two spots to make sure the parents are informed and also the teacher tells you if they are there or lets the other teacher know if they've gone. So we get a note in their 'daily activities log book', 'incident report' that includes what action was taken, how it happened etc, and the teacher informs us. And it's for anything even trivial stuff like a scratch.