Couture vs. Belfort frame by frame

Just rewatched this fight in frame by frame slow mo and it goes like this. Belfort throws a right jab, randy ducks away, belfort throws another right jab, randy throws a right and it lands in the cut area, randy closes the gap and accidently head butts Belfort at the cheek bone area. IT IS VERY CLEAR IN FRAME BY FRAME, that it wasnt the head butt that caused the cut.