The real issue is that they called fouls that were no-calls in the 1st half, and the C's were in the penalty just inside of the 6 minute mark.
That's what I didn't like. I mean, if you go by the rule book, there are probably 100+ fouls every game. Usually, though, the refs let a certain number of those fouls go, to allow some flow to the game. The teams figure out how quickly the game will be called, and then adjust to it.
In this game, for three quarters the game was called fairly loosely, with both teams allowed to play physically. Those were the established rules of the game, essentially. Then, in the fourth quarter -- with the Lakers trailing -- the rules suddenly changed. The refs started calling ticky-tack fouls, especially on the Celtics. To the extent that there were bad / missed calls, those went against the Celtics.
I usually don't buy into the conspiracy theories where the refs favor one team to win. However, Game 7 was one game that I truly believe that the refs changed their style of officiating to achieve -- or at least favor -- one result: a Lakers victory. The Celtics suddenly weren't allowed to play their defense, which made it very likely that the Lakers would be able to catch up.