Fun stuff, but both guys have an odd way of reloading the ARs... rolling the gun to the left? If anything, that's going to trap an empty case in the ejection port... and the extra maneuver doesn't hurry things up. Just drop the empty mag, keep the stock under your arm so the gun offers resistance, seat the fresh mag and do a push/pull. And keep your eyes on the threat, not the gun!
Mr. Green Shirt does a creditable job with his malfunction at 1:16, but note how that single-point sling inhibits using the left hand to work the charging handle. A 2-point sling would provide extra hand/arm room to manage that manipulation.
Where did the guys in the video get their training?
Wish I could shoot a handgun that fast, though!