There’s no question that Anthony Johnson has done nothing but impress since he returned to the UFC, but a new video is sparking debate as to whether an accidental headbutt, may have dropped Alexander Gustafsson at UFC on FOX 14.

As you know, Johnson stunned Gustafsson early on into their headliner on Saturday night, and eventually took “The Mauler” out with a brutal series of punches from the top position. While highlights of the fight have been circulating for a couple of days, it seems like the one below in particular, is raising questions about whether Gustafsson took the worst of a headbutt. In the exchange, Johnson also appears to land a right hook.

Following the fight, Gustafsson was apparently asked about a possible headbutt, and stated (quote via MMA “No, I didn’t feel any headbutt, what do I know?”

An angle from above, seems to show Johnson’s head clashing into Gustafsson’s, but not until after it hit his shoulder. Another angle from the side appears to show Johnson’s head hitting Gustafsson, but only slightly.

The video sparking all the debate is below. As a result of Saturday’s win, Johnson will move on to face the light-heavyweight champ, Jon Jones.