"Why would I go to the funeral?"
It was a simple reply, and not laced with too much emotion (probably to keep us from sensing too much about it), but I could see enough of a tinge of repulsion in it that I kind of expected Kate to spit on the ground after she said it to seal the sentiment. A lot of other fans sensed it enough that many voted for Ben being the dead-guy, since he has done so much to earn the hatred of any of the 815ers.
I wonder what happened between Kate and John that ticked her off so much? Could it just be because of all his efforts to keep them from leaving the island? His general half-cocked, explosive craziness? Or is it something that Locke did as the alias Jeremy, after they left the island? Makes you wonder if John might have tried to abduct Aaron somehow when he went to talk to Kate, on his off-island recruiting mission. He could have gone to her to convince her to take Aaron back to the island, she says no, and when she goes to get some iced tea in the kitchen to politely send him off, he sneaks upstairs to try to nick Aaron and she catches him and freaks out. As with everything else, we'll just have to wait and see.