Hmm, depends on how you define rotten I suppose.

In SA, part of the Selous Scout training includes killing a baboon and hanging it in a tree for three days, then cooking and eating it. I've not had baboon, but I reckon that hanging a dead one in a tree for three days probably doesn't improve the taste much.

I also wonder just how rotten the carcasses were if it was cold enough to give him frostbite. I doubt he was exposed to any really nasty pathogens, most likely he gagged maybe on the smell or the texture, given that the animals were likely whole. Even cooked, most animals don't taste real good when they aren't dressed out first. In any case, he wasn't in a starvation mode yet so I don't know why he started eating them so soon.