Interesting to see.. the guy was fighting it / holding that rifle so tight too.
About 26 years ago, I made a 458Lott on a Brno 602, got the loading data from Gregor Woods gun editor of Magnum magazine, and Nick Harvey here, fire formed the cases,, and mounted a 1-4x scope way forward on a bridge mount, so I had 5" of eye relief.. but every 2nd or 3rd shot I got a cut eyebrow, and had to wear safety glasses.

Decided to put a video on a tripod side on, and see what was going on... result in slow mo, frame by frame showed this..
Me- being 84kg the rifle came instantly straight back 5" and touched my glasses, then my body rolled back, and rifle barrel tip up about 12".
Joe - being 110kg the rifle came straight back 4" then body rolled back a bit less, and rifle barrel tip up about 5".
I went down a step to a 416 Rigby, and scope missed my head by 1/4" each time, perfect.
Years later pre season I had a knee meniscus trim, so took the scope off my lightest rifle, and practiced at 50,100,150,200m with open sights, and we were surprised how we could group good enough for DG... so I then used open sights for guiding next 20 years.. and experienced 465, 470, 500NE, 505 Gibbs, 500J and 600NE recoils..!!