OK, maybe not the majority, but many refs would have stopped it inside the last 20 seconds. Bute barely has the strength to lift his arms, he can't even hold and his legs are totally gone.

The ref is supposed to be impartial. He isn't allowed to take the time of the round or the fact that one fighter has dominated into account. That would be showing favouritism and also be a danger to hurt fighters.

I guess Andrade is mainly unlucky with the time. Bute could clearly not continue (although he rightfully won according to the rules). He may well have fallen if asked to walk forward.