The pic Dana posted of Reem's lip on his IG is pretty gruesome, his lip is literally split in two.
And we've seen Overeem get knocked out so many times already, don't think he would've got up at all if Jairzinho had a chance to punch him again. Gotta feel bad for Overeem though - he was winning on the judges scorecards and was on his way to a UD, but he should have kept his hands up.