Wow there's a lot of good stuff going on here. Holy shit that flat left wrist! So many slicers would kill for that! Awesome swing path, nice square club face (people think that's shut but they don't know what they're seeing), a great in-to-out path. Awesome.

However, what is not well understood is that the rotation of the hips is the release of the club. You don't do it with your arms, or your hands, but that's what's happening here. What should happen is your arms go through as a consequence of the release, which is your hip rotation - which is a consequence of your right leg rotating.

If you stop the video there in the 5-second area, you will see that in the middle of the downswing, you are up on both of your toes already, before your right leg has done anything, and so, before your hips have released. here lies the problem. You can't release the club because you're not releasing your hips.

What that means is that you have developed a swing where you don't release, and flip the club shut to time it. Sometimes it flips shut and you hit it ok, and sometimes way shut, and you get a pull.

So, how to fix. This is a good one because you, sir, have awesome arm action. I'm jealous. But, at impact and after, that release can't be no hip rotation and flipping with your wrists. You need to have better right leg action so you aren't up on your toes and can release your hips. Here's Mike Malaska, a Nicklaus swing student, on the right leg and what really creates hip rotation and release.

When you start releasing your hips, then you will have real rotation and your brain will let you stop flipping the club shut because all your other arm action is - seriously, not kidding here - really excellent and you should start releasing the club more naturally.

Hope that helps. Cheers!