Similar to the overhead photos. This was a multifaceted FUBAR (F**k'd up beyond all recognition). Had Perez not changed lines Masa probably would have forced contact at or beyond the apex of the left hander given his speed, ie. Masa's fault. Had Perez made his move earlier and not in the braking zone contact might have been avoided altogether giving Masa a chance to react. So, given the outcome, I think the decision to penalize Perez was the "most correct" one: