I remember the one time I lost it I threw a chair across the room, narrowly missing the head of the instigator.
Then I stormed out of the room and went home.
After that my friend told me that I was really scary. Thing is, I don't even remember what the hell happened to make me so angry.
But anyway, to answer your question, I think it's highly probable that an NF will end up hurting someone really deeply if he loses control, but in my experience I usually become afraid that I've done just that and ingratiate myself back. Or act all normal to suggest that I haven't lost all respect for the person. I think it's pretty much something common to NFs, that they don't like to be in discord with others?
Anyway I'm usually not angry at the person himself. Just parts of his character.