Yves Lavigne not sure if Belcher's slam on Cote was legal

During the Saturday Night's UFC 113, Alan Belcher caused an upset when he locked in a rear naked choke to an already dazed Patrick Cote. It seems it was the slam before hand which is causing some debate.

As far as UFC rules to, it is illegal to spike an opponent onto their head, ie. Slamming them onto their head or neck. While it appeared at first that Cote had landed on his neck, later replays showed he had landed on his face. In my opinion though, it seemes to me that Belcher had the intention to drop Cote on his head illegally, although he didn't.

Sportsnet.ca however had this to say on the subject:

“[Patrick] Cote, meanwhile, complained that he was spiked (planted head first into the ground, which is illegal) just prior to being finished off with a guillotine [Rear naked choke] by Alan Belcher, but his face hit the mat first, which technically makes it legitimate, though referee Yves Lavigne (who didn’t officiate the fight) wasn’t so sure.”

While Lavigne wasn't in charge, the refferee was sitting ringside watching. Had it been another official on another night, maybe the fight would have been stopped?