Vote: IS
...oh, wait...
Anyway, I'm not surprised that Antrax died. While it is vastly different from their other kills, the mafia are now looking for a doc. And since they only had a certain chance of getting them, and Antrax was using his Jedi mind tricks they might as well have killed two birds with one stone.
I don't know if it was you who really deserved that notch, though, Antrax, but hey. You're dead now. And you always have to say nice stuff about dead people, so you can keep the credit.