Looks to me like he was breaking his grip to the left thus hitting to the targets right.
Maybe he’s left handed? Know I tend to pull slightly to the right until I get the rhythm back.
It just occurred to me. If he’s sat in the drivers seat, and Brown went for the gun, it’d have to be on the left. Too easy to grab an arm going over your body, otherwise. If he was passenger seat, maybe Brown strained the officers arm in the scuffle?
Just throwing things out right now. We don’t know and won’t know for a while.