The legs don't lie. He was wobbled.
Do you think this one was 100% fixed too? Because Forrest has eaten much harder shots than that before.
How about this one?
Aldo got slept with a short quick shot going backwards. He closed his eyes and threw a bomb. He didn't expect Conor to beat him to the punch with a short weak shot, and he was basically blindsided with it. Conor said it himself also, "timing beats speed, precision beats power", this is exactly what he meant. Floyd used speed and precison to catch Tenshin off guard, and Tenshin never recovered. Not that he had any chance of winning beyond throwing or feinting kicks to catch Floyd or throw him off his game.
It's the one's you don't see coming that get you. Tenshin expected Floyd to play defense.
Watch any Nick or Nate Diaz KO, they don't exactly swing for the fences but they hit the button consistently and sometimes the punches are deceptively harder than they look, and harder than the ones from earlier in the fight. Those are the ones that get you.
You can hurt people with power shots or with good timing and precision.
Also Floyd (who's known for having "pillow fists") doesn't usually fight with 10 oz. gloves on, the smaller the gloves the stronger the chance of a KO, add in the size advantage and there you have it.
Rizin wanted Tenshin to win, or at least look decent, there's no doubt about that. Them paying him to take a dive would be like UFC paying Conor to take a dive against Floyd, in the UFC, after paying him a boatload of money to come to the UFC for a one-off.
Rizin paying Tenshin to take a dive makes no sense whatsoever, on any level. There is zero reason for anyone to pay Tenshin to take a dive. Except for Floyd and come on, Floyd wouldn't take the fight if he thought he was going to lose and had to pay off his opponent.
Rizin wouldn't have made that much gambling on the fight, compared to what they spent. And Tenshin was crying so why would he throw it?
At least your theory is plausible though.
The only odds I saw were on a finish, but I didn't look.