In lieu of a formal written protest via typed letter to the state athletic commission, just go ahead and beat the hell out of the referee in the cage. If you ain’t cheating you’re not trying and if you disagree with the call in the cage just start wailing away on the man responsible for ending the fight.
From Aggrelin Cage Fight in German, here’s the fighter protesting an early, late or crazy stoppage the only way he knows how. Work the body, open up for head shots in the latter rounds.