I was hitting some shots last night and experimenting with different things. I know we have had some discussions about this shot and the trickiness of fixing it.
As you can see, when you get a slow motion video of what happens, the mystery disappears.
After seeing hundreds of videos like this, the top cause is that the swing path goes outside in. The fix is super simple and after seeing this type of video there is no mystery.
I can get another video for how to fix it with the same slow motion video.
I LOVE it! Face is closed. Outside in. This is EXACTLY what happens to me because when my core wears down I tend to not turn my body and arm swing the club to the top, then the club travels out-to-in and poof.