Dude, he could have SMASHED and PULVERIZED that knob in a single blow. He was taking it easy on him as he was told to. I have been in a very similar position, where you are put in a situation like that, the other guy becomes more serious, yet you can't do much as you are that much bigger and would look like a bully doing so.
No matter how he created the physique, he took it to an extreme level, and generates huge interest. But even now, if you put him and say Jay on stage, I dare say he would look bigger, and better than Jay.
As for having oxygen debt, again, I can sympthize with that. At my biggest, I felt dam heavy, and was damn strong, but that kind of grappeling that he did would have left me feeling the same as its not something a guy that size and/or strength trains for.
The foolish thing he did was getting caught up in the show, and not putting a stop to it. You can see how this can happen, on live TV, cameras on you, foreign language, trying to portray a good image, be the nice big guy, etc. Seriously, it could have gone on for another 5 minutes and he really might then have been struggeling for oxygen as a body with that mass is not tuned for that kind of exertion.
