Oh I dunno, he's already a cheat, a user, and a summary executioner. If evil Kirk were to cross that line in the Nu Universe, who'd even notice? Even NuSpock believes in summary executions.
Huh?
They were supposed to save Nero (and his big, dangerous ship?) at the last minute and put him on trial?
Well, they (nuKirk and nuSpock, or anyone on the Enterprise) could have at least tried.
Or, since there was a black hole forming that was going to consume their starship soon, they could have just ran away to save their own ship, acknowledging that there was nothing they could do for the Nerada.
But instead of those options, they actual went
out of their way to attack the Nerada, to help along its inevitable destruction. Talk about kicking a man while he's down.
No matter what crimes Nero and his crew were accused of / guilty of, the Nerada was not an imminent threat to the Enterprise at the time and they, therefore, had no right to fire on the ship. (I’m talking about after the creation of the black hole, when nuKirk and nuSpock were already back aboard Enterprise.)
nuKirk and nuSpock had taken it upon themselves to be summary judge and executioners, very much
not in keeping with Starfleet ideas.
But this does happen from time to time in Star Trek movies. Remember the end of Star Trek: Insurrection? Picard and Ahdar Ru’afo were on the collector together. There’s about to be a massive explosion (or one already in progress, really). The EE swoops in and beams Picard off the collector just in time and Ru’afo dies in the explosion.
Why? Why didn’t the EE beam Ru’afo off the collector with Picard? Certainly it took more time to lock on to just the one specific lifesign. Picard wasn’t wearing a combadge or anything to lock onto, afterall. It would have been easier to just beam over all lifesigns within the area, both Picard and Ru’afo. So, do we think that the EE transporter operator went out of his/her way to select just Picard for beam-out? They really took the extra time? In the middle of an explosion? And under whose orders? Not only declaring themselves judge and executioner, but also risking Picard’s life more than necessary (in the extra time it took to ensure Ru’afo wasn’t beamed up), just to have the buy guy die instead of getting captured.
Because the Hollywood ending required the bad guy to die.
[To play devil’s advocate a little: Maybe Ru’afo was standing in a bad place where his lifesigns didn’t register or something; but he was only a few meters away from Picard, so that’s not likely. It’s never explained on screen.] Either way, Star Trek 2009 was worse.