Colin has always been a good sportsman. I am guessing you are referring to his comment about almost running into the back of Corser or Bayliss? I noticed the very same thing while watching the race. There were several parts in the track that Colin didn't slow down at all, and everyone else was, or at least backing off the throttle, ie, where he passed Bostrom in race 2.
Even though I think his comment was OK, and not malicious, he doesn't usually do that. It's usually nice comments all around, about the track, riders, and how hard it was to win, etc. Bostrom on the other hand is not usually so gracious and non-, but he is changing it appears, which is great to see, because he's developing into quite the rider (and moreso, he's learning the tracks).