The video stated the shot was 397 yards with a 140 gr TTSX from a 280AI. Putting that into RCBS.load's ballistic calculator and assuming a muzzle velocity of 2970 fps puts it at about 2130 fps when it struck. That's faster than the minimum velocity I've seen for Barnes TTSX to open up, but like BC30 says, it was a high lung shot and missed any heavy bones to help it open.
This explains it to me. Most bullets work if used right. Nothing wrong with TTSX's, but it was the wrong bullet for the job in this case. Copper isn't a good long range bullet. Bullet speed was too slow at that range to get any expansion.
