While it's not 'official', most (non-Miami) NBA fans believe that the NBA had some lean towards the Heat in the final. It's believed that the NBA needed the Heat's big three to win to ensure that they seem relevant, so they got the officials on their side. I don't have a link to the exact stats but there was a large discrepancy between the fouls called on the Heat and the fouls called on the Thunder. Along with that, people that believe the game was fixed point to a video showing the Heat coach high-fiving a ref. While the video is iffy, it's enough evidence for some people (http://www.youtube.com/watch?v=iHNnv8sVijE).
Personally, I think it was swayed a bit, because of some very dubious calls. I don't think the 'high-five' incident had anything to do with it.