I think right now the guys feel like they're starting to catch their second wind, and Doc wants to keep the momentum going. These games are very important, and Ray has carried this team on offense lately. It's vital to play like every possession of every game is meaningful (something the Cs weren't doing for a large part of the season), and Ray's minutes indicate that that's the team's mindset. Taking that into consideration, along with Pierce's injury, and Robinson being unavailable, I give Doc a pass today.
However, I would like to see Ray's minutes lowered once Nate's back and ready to play extended minutes. Hopefully Marquis continues to play like he did today because this was one of his best games of the year - aggressive on taking it to the rack, good effort guarding Melo, even made a couple jumpers. That would also make it easier to find Ray rest.
By the way, I think the story of today's game, besides Pierce struggling, was the way Rondo played. I don't care what his stats look like (he got another double double), he didn't bring it today and if he had played better I thought Boston could have hung around and possibly stole the game. He made life a lot harder for the team by making some poor decisions in transition, and seemed fatigued most of afternoon. He was god-awful on defense - it was embarrassing seeing the much older Chauncey Billups drive by him at will.