I don't see that it makes a difference. Nero was already dead, by his own choosing. If Starfleet wanted to slap Kirk for endangering the ship while it waited around firing every last torpedo from its banks, they'd probably have cause to do so. But they didn't.
I don't see stepping inside a person's private headspace to psychoanalyze his motives for doing something if he's committed no crime. If someone told me I couldn't make a sarcastically understated truthful comment just because I was already suspect for things I had done or said in a previous scene, I would probably do just that.
I also don't see holding someone to a different standard because of ones (presumed) knowledge of his race or cultural values. Even though I have a very vague recollection of the Klingons once trying to do that to Worf when they had him tried on DS9 (and it seems to me it was finally agreed they were just trying to stir up trouble).