As a Henry owner of many years, I quit watching that video half way through. Guys like him are dangerous.
You've got more concerns that a proper crimp on the bullets. Dropping the rds down the tube vertically could cause a detonation with sensitive primers like Federal. The proper technique is to hold the rifle horizontally, muzzle downrange, then carefully lower the follower being sure not to lose the grip on it.
I've been present twice when three rds detonated after the shooter slapped the nose cap shut, and I know of one other. In one case, it was after 10 rds had been loaded, in the other, five rds. You'd think that with 10 rds, the follower wouldn't have that far to fall, but it happened. With five rds, that heavy follower had some energy behind it.
You can learn a lot from proper videos, but poorly made videos showing dangerous techniques need to be called out.