Examining the “bullet hole” in the vid...
Comparing it with another higher-density pixel photo at that same moment, I think it more likely that “hole” is some artifact on the SS agent in front and protecting him, on the sleeve of her jacket. The two jackets are almost the same color, with Trump’s a shade lighter blue, or with more sheen or something. Following the lines between the jackets, that hole really looks like it’s on the SS agent’s clothes.
It looks like a button to me.
I’ve squinted at the black mark and it looks like it’s just above the agent’s sleeve and in the lighter blue sleeve on Trump, but I know that digital images and perspective can be a little wonky. About the time of the first shot, his right shoulder lifted up just a little, and about the time of the second shot, he grabbed his ear. No matter what, the grazing on his head tells us that the assassin was all too close to succeeding.