There is a lot of sense to the whole Carlos corrupted by Nemesis. Jim has said repeatedly that people corrupted do not behave the same, they change fundamentally. They start doing things against their nature. I really don't think Carlos was changed by the Molly experience. He wouldn't hold that against Harry in any case. On the other hand, suddenly Carlos is acting all suspicious of Harry, showing up in the middle of the night to ambush him? That doesn't sound like the Carlos of old. The one who put his life on the line and got himself locked up to support Harry during Changes? That doesn't jive.