I watched it too and saw the first action blow apart. The action looked like a beefed up Marlin to me.
The 500 S&W is an ultra high pressure hangun cartridge. I know operating pressures are equivalent to that of high powered rifles. I am sure some poster will let us know exactly. It will take some serious engineering to come up with lever gun designed to take such extreme pressure.
There are many hunters who like high powered lever guns. Wish those folks in AK the best.