Changing some details. My child went on a residential trip and was threatened (not hurt, but threatened) by a child with some behavioural difficulties with a weapon. Class teacher told me all and I am satisfied it was dealt with and my child was not hurt. Class teacher is my friend, by the way. Other parent was told "There was a little incident, but was dealt with" - no details.
I think maybe I should have insisted on a more rigourous "dealing with", and if I was other parent I'd have wanted to know the details. This was a while ago (couple of months) but sometimes I find myself fretting about it.