To play devil's advocate...
About the Foul Discrepancy
The Cavaliers are a younger, more athletic team. The Celtics are an older, jump shooting oriented team (though the Cavs have good shooters, too). Also, the Celtics don't have anybody like Lebron James who deserves to be near the top of the league in free throw attempts. Rondo could be but he'd have a hard time finishing the season if he tried.
About the 4 calls sent to league officials
I'm sure in most NBA games there are bad calls for both sides. I'd also guess that in most games 4 clearly wrong calls could be sent to the league office. Refereeing such a fast-paced sport is difficult.
Now with that said, I think the refereeing has been inconsistent and generally favored towards the Cavs (with some exceptions). This doesn't really come as a shock because NBA home teams have the best W/L differential of any sport. I attribute this mostly to the officiating. What drives me crazy is this has been going on for so long and nothing happens.
Heck, Donaghy even said Bavetta was notorious for letting losing teams back in the game in the 4th Quarter. It happens again last night and there's no national media attention. Incredibly irritating.
I will say it was nice in '08 when the Celtics were ref favorites. Unfortunately, it seems like the only two likeable players now are Rondo and Ray. Pierce, KG, Sheed, and Perk aren't going to get any borderline calls.