I believe the details of the hunt are unembellished and I don't believe this video has been circulating for "more than 7 years".

The question on the Nowatny would be was it made or licensed by WR for their propriatary cartridges, in particular the Super Magnum Explora. If the gun had original 2 3/4" chambers it was certainly chambered for a magnum paradox cartridge but which one?