Lol depends on how it's used.
If you use it tactically, it's fist of havoc.
If it's used because you're about to die or as a twitch reflex to kill one dude because you think [i]he[/i] might kill [i]you[/i], it's a panic fist.
Either counts as a kill though, so whatever lol. :P
I don't play a lot of crucible; but I've been known to still have my super when the game finishes because I like to use it on multiple enemies...
I will say that I've run into nova bombs and blade dancers activated just on myself as much as I have the fist of havoc... Not sure why the fist of havoc is the only one branded as a "panic" super...
Well, I figured it would avoid fights if the thread picks up (it probably won't, but just in case lol).
Then again, there are the Destiny forums, [i]of course[/i] people are going to fight lol. :P