I’ve always just called it a slip stroke lol. I remember reading about what an actual slip stroke was and being confused when I tried to do it. I haven’t revisited that thought since. Maybe now
Letting the cue slip on the way out comes naturally on some shots. Hard or soft. There’s a hard shot at like 2:00 and a soft shot at 5:38 that you can really see.
Well done. Normally, I don't use it on follow shots like yours at 5:38 but it's still a tool I have. I'm pretty sure that could be traced back to the mud ball as it does just fine going forward on it's own.