Damn, I'm gonna have to try that. The fact that you can pull that off on expert has me a little worried lol.
I have been trying for ages. I didn't get it on advanced and stepped it up to expert.
I had him in mount for about 2 minutes punching him in the face. in the last 20 seconds I rocked him and slapped it on. I bruised my hand and probably broke the controller trying to get a submission previously but I did it fairly lightly(wasn't expecting to secure it) but full circles and he tapped. I haven't done it on any skill level aside from beginner apart from that though.