If you turn into a guy from the outside of the last corner on the last lap that is usually the end result.
Dirty pass? Hardly. Watch Haslam, Melandri or Sikes on their passes and the places the passes were being made; on the curbing out of nowhere with the guy having no clue you were there until there was contact or you were pushed wide.
Haslam was wide, as in there was still asphalt between his knee and the curbing, at a World level event that is enough to warrant making a go at it, at your home race.
Rea did the right thing IMO; he went for it. The ongoing trend in these race threads is better racing this, better racing that... well folks that was better racing two races that were filled with boat loads of excitement. Sure it sucks that someone went down (and I am glad no one was hurt), but that is not all Rea's doing, Haslam was leaving doors open for a lot of laps before and some of the blame for the situation lays on him for not protecting the line.
Bottom line, Jonathan Rea showed everyone what it takes to win a WSBK race and the Flying Unibrow learned a little bit about racing on the last lap. I don't doubt he'll win one this year, and I highly doubt there are hard feelings between the two.