Never happened. I watched the video.
But the video doesn't show what happened at the front of the vehicle because the vehicle itself is obscuring the view.
Absent the ability to view that segment of the video, the gap is filled in by questioning one of the two parties who were involved in the shooting. Because Arbery is deceased that only leaves Travis McMichael's although the father if he was in the bed of the trunk may have been able to view what transpired, however I don't recall him providing corrobarating testimony in support of your allegation that Arbery attacked first and that Travis was only defending himself (actually this point is moot because it's already been established that the McMichael's were the aggressors since they chased down Arbery)
How is it possible that you watched a video and saw something on it that isn't there?