I'm not worried about him killing anyone -- that was an extreme situation. But the trouble is, given the circumstances -- twenty-one students competing for the 'honour' of Death Eater initiation -- I can pretty much guarantee you that he will encounter buggers who deserve it.
If he can't control himself -- no matter what he hears them say, no matter what he sees them do -- then he can't do this.
Re: Private message to Sirius and Kingsley
If he can't control himself -- no matter what he hears them say, no matter what he sees them do -- then he can't do this.