1. What's the purpose of the video. And is the guy mumbling while making an instructional video...? As someone else said, if there was no AD, what was the purpose of recording him showing the shot shells to the camera while mubbling something?
2. Purposefully non-level table.
3. Watch him flick-roll the shell into the others that are stacked in a row - painfully obvious he is trying to get the last one to roll off the table.
4. The explosion doesn't occur where the shell fell and would have landed.