"Before the fight, my trainer, Javier Capetillo, my former trainer, put a knuckle pad made of gauze on my hand," Margarito said yesterday. "I learned later the knuckle pad had something irregular on the inside but I didn't know that truthfully in the moment. The knuckle pad didn't feel different to ones he had put on my hands before. I never felt anything hard or irregular. So basically the same kind of illegal knuckle pads have been used in other fights by Margaritos own admission.
I don't think he was implying he's been using plastered pads, I think he was implying he couldn't tell the difference.