I think O'Malley's sour grapes stem mostly from the fact that he thinks the guy that beat him wasn't really good. Well, the thing is, most top fighters have one early loss to a relative unknown or a journeyman. Rampage lost to Marvin Eastman in his first pro fight, Chuck lost to Jeremy Horn, Randy lost to Overeem's bro, Anderson Silva lost to Luiz Azevedo, etc. It's kinda part of their trajectory towards greatness, in the early days of their careers when they develop.
O'Malley sounds like a guy with that archetypical "millenial" attitude...wants immediate greatness, but won't accept it when the going gets tough, because he had this vision that he'd just run through guys one after the other, get promoted like crazy and be drawn a path to superstardom and championship level fights that is meant to be flawless. Now he lost to a guy he considers as a journeyman, and is making a shit ton of excuses and crybaby bullshit. And that's why it's so satisfying to see him lose.