In the third round, Alvarez connected with illegal knees to a downed Poirier. Dean stepped in and called off the fight, resulting in a no-contest being determined.
Many felt Poirier should have been given the win because the strikes were illegal, but Dean disputes that.
“I stand by that, ruling it a no-contest,” the veteran referee said on The MMA Hour. “I believe (Alvarez) was fighting in earnest and thought the fighter was not grounded. There’s no way I could say for certain.
“I attempted to warn him before he went in, but it was loud and I can’t say that he heard me.”
Alvarez connected on three knees to the head of Poirier, with the last being illegal and forcing Dean to stop the fight.