I also think that it's possible it was fixed, but I'm not sure, I would like to discuss and analyze this possibility tough.
About you arguments:
-Well, if you are 550 lbs with a 30 seconds gas tank and a quicker, faster, better conditioned 170 lbs opponent throw himself at your feet, would you not try jump at the opportunity to use your weight and squash him?
You would probably think that's your best chance, while on the feet he can run circle around you until you are tired.
-Royce doesn't try to armbar Akebono tough, he put him in an omoplata, those are completely different moves.
Plus Hong Man Choi is surely much stronger than Akebono, the guy is severely obese, I think he would struggle a lot to just lift himself from the ground, let alone with another person hanging on in an extremely mechanically disadvantageous position.