I agree it was a good stoppage. When I finally watched the fight, I was thinking “Ok, so we’re just going to see which punch puts him down, huh?” about 3 seconds before they actually stopped it. McGregor wasn’t taking punches, he was getting his clock cleaned thoroughly, and couldn’t get his arms up. He was physically capable of raising his arms, he had thrown punches earlier in the round, but his brain wasn’t managing his body that well anymore. It’d be pointless to find out which punch turned off the legs, as it was just a matter of time before that happened.