I watched it in slo-mo and it appeared to me he reached in. The bigger point is that it wasn’t the cops gun.
I also viewed it frame by frame. Again, if he’d grabbed a gun from the inside of the vehicle, it would have been in his hand when he exited the vehicle and the cops would have seen it immediately. I’d bet a cup of coffee he drew from his waistband after exiting the vehicle and during the struggle outside the vehicle.
In fact, go to near the end of the video, watch frame by frame starting at 9:58, you can actually see part of his right arm and it clearly appears he’s drawing from his waist area. Subsequently within seconds the suspect raises up his gun and starts shooting.