It's got little to do with courage and nothing whatsoever to do with wisdom. The fact is, I was in the Navy for over twenty years, and so unless there happens to be a soldier or police officer in the vicinity, I have to accept the reality that I probably have the most chance of anybody around of dealing with this type of situation. Combat training and experience, if limited. I can't see how a person can stand back in that circumstance. It's different if you have no idea what to do, or no special skills or if you think somebody better equipped will be on the scene momentarily. It's also difference if you know there's no chance at all.
When lives are in danger
Though your own is in doubt
You have to go in
You don't have to come out
I'd never throw my life away - but accept a risk that might pay off - that's different.