He most certainly used size as an excuse. He said "diaz's size allowed him to absorb strikes that would have ko'd 145lbers"
Regardless of whatever excuses he has, none of em can ever be valid after he talked how much he talked. Everything from talking about ppl's "basic movements" to "1st exchange predictions" to "making up injuries"...dude put his foot in his mouth and his fanboys put his _ in theirs...
He needs to be stripped of his title if he doesn't defend it by dec, its bs that he can hold it up so he can attempt to get revenge. Hell after Diaz washes him again he might retire.