Yes, I see your point!

Anyway, there are several ways to act in good faith without risking too much. If the thing escalate so much, it can be good to provide some anonymous recordings or equivalent to to setup the cheater. AND, if the thing escalate so much, it's likely that the events are repeating, so there may be later chance to grab proves or frame the guilty.

In general, I think people are not so violent, but your point is good!