i found the video to be a mix of good and bad. lots of good thoughts on cutting and stabbing, then he says something like "a side kick to the knee will instantly break your leg".
other things i didn't like:
-not a huge fan of the footwork he demonstrated.
-i don't really like how he suggests that you should lead with your unarmed side. i thought leading with your knife would be a better idea?
-he has this weird idea about balancing your hips, and uses a bowl of water to illustrate his point.
other than that i'm pretty sure he knows how to kill someone with a knife better than most people.
my older brothers are big fans of pig hunting. they go out with dogs and big knives, hunt down the pigs, set the dogs on them and close in to stab them to death. i went along for a week of pig hunting one time and saw how they used the knives, which was quite similar to how "animal" suggested - stick it in deep to reach something vital like the heart (with the pigs it was usually through the top of the ribcage at the base of the neck), then kind of wiggle it about to slash things up. blood pumps out like crazy, splashing everywhere. i did one myself.
no slashing about on the surface, stab in deep and mess up the insides for a quick kill.