Fighter cannot be saved by the bell in the 12th and final round, that is the rule.
This is why if you watch the fight, even though the fight is over (on the clock), they don't ring the final bell until after the ref says wether or not Bute can continue. They were awaiting a verdict.

Bute was clearly out and the fight should have been stopped. So I won't only dispute the long count, but I'll dispute that the only reason the referee DIDN'T wave the fight as a KO for Andrade is because he knew there was no time left, and by saying Bute was able to continue, he'd win. It's bull shit