If you stop motion at the frame marked with the time 5:03 you can clearly see that the lifter arm is missing altogether. Obviously the gun was taken apart at some point and the arm and carrier were removed. Maybe it was used as a toy. Stranger things have happened. Back in the mid 1980's, a friend found a 4 3/4" Colt SA marked COLT FRONTIER SIX SHOOTER on the barrel. The caliber of course was .44WCF and the serial number was 111111. Yes, that's right. It was found laying on top of a large round boulder on a steep hillside. One grip panel was missing, the bore was plugged with a lead slug and the firing pin had been filed down so it wouldn't set off a live round. It was pretty obviously that it had been used by some youngster as a toy.