I've watched it a few times, and the one thing that hits me as being most off balance is when she strikes him, and when she's racking the slide on her pistol.
Something about her entering the frame and striking him seems off, maybe its in the speed we went from "not here" to "suddenly here and smack" in such a quick move, or maybe its in her actual striking movement, how she comes off balance to reach up and strike him...
And then, just with my involvement with law enforcement I pick up on these areas, she seems very unnatural, uncomfortable even, with the gun. Assuming it's her pistol and she lives the *insert falsetto* "thug life" she seems to be holding it in the same regard as one would a TV remote, or an airsoft pistol, ie, a mostly harmless chunk of plastic. I would expect someone who pulls out a "piece to bust a cap in dat foo's ass" to have more of an idea of what parts move. I get, that it may be a solid piece replica in which the slide doesn't move, but in the movement of racking a slide I don't expect anyone to return the slide to the forward position by hand, the springs internally are rather strong, and in a hurry to chamber a round, I would expect to see someone yank the slide back and simply release it. To summerize, she looks almost like she's fumbling with it. Not a huge thing, just something I happened to notice, and may infact not even be an issue, but I feel with the focus on the gun at that point, its a noticable action. I debated also bringing up trigger discipline, but seeing as this is an "outside the law" type shooting, I wouldn't expect the real world counterpart to practice proper trigger discipline either.
Now, the whole thing did have an over all good feel though, please don't feel like I'm griping over the work! Your actress as the director had a good conveiance of mounting frustration, and your actor as the actor pulled off the douchebaggery very well, both with out being over the top, and all without sound! Perhaps, the sound added would pull away focus from the striking and the chambering, as well, since "Sound Fools the Eye"