I don't like Jaekyung as much as all of you but I've seen enough MMA fights to know that if a champion is defending his belt and was able to remain standing after 3 rounds and didn't get his sht KO'ed, submitted or overly powered , he gets to win the match. Jumin will have 1st options for a rematch as per contract but since he's the challenger, he and his camp should know that unless he wasn't able to do anything of those three, he definitely should not win.
Much as I want to see Jaekyung's sht KO'ed, Jumin has to train harder and get better strategy than that.