The ending to this fight is the definition of controversy. Dawson was doing well and neither man had established dominance. Midway through the second round, Dawson threw a combo that missed and Hopkins followed up by leaning over Dawson. Dawson proceeded to shrug Hopkins off with force. Hopkins went to the canvas and was hurt. His elbow was screwed and he couldn't continue.
The replays showed that Dawson didn't just Shrug him off but actually had a hold of the back of Hopkins leg while he forced him down. The ref ruled that there was no foul so Dawson won a TKO victory when Hopkins couldn't continue. There was chaos in the ring even before the official announcement was made.
Was Hopkins "acting" thinking that it would be a no-contest? That cannot be answered but he is known to have had some "acts" in the past. Should it have been a no-contest because the ref missed a blatant foul? I don't know.
It would be appreciated if someone could post a gif of the action because I couldn't find anything yet.