Half step on Mag. Looked just like you say. Had he just kept going towards the hoop, probably would have gotten a call.
Not sure if he saw Keita or just didn’t feel like he had a good angle to make the basket or what. But he paused, which allowed Mag to square up on him and force the weak fadeaway shot. Which was also rushed, probably because he did not realize how much time was left.
His best bet looked like just driving right to the basket and trying to lay it in and if not a better chance at drawing a foul call. May have been blocked by Keita but still a better chance for him to get a call.
BYU was the better team all game. Poetic Justice that last play went their way.