Because throughout all of the following... - Pascal - Taylor - Dirrell - Kessler - Abraham - Johnson - Ward ...he never showed any serious signs of being past his physical decline. So, I don't think the Ward fight - which wasn't physically gruelling in anyway - would have all of sudden pushed him past his prime. It's possible, but I doubt it. He even said so himself that it didn't feel like he had been in a fight. He was just thoroughly outclassed. That's all. He'd have recuperated just fine for Bute.
Froch is done like the guys above say... Bute destroys fighters up to weight in and the actual fight only with his presence. They already lost the fight previous to entering the ring.
Already I've had to battle with a couple of posters that have said Froch is no longer the same fighter since Ward, and that Bute beating him now, won't mean as much because Ward's already done it. He's shown everyone the blueprint on how to deal with Froch, is what they say lol:atsch)