This guy is nuts. I fished when I was younger and encountered a few snappers before; they are the nastiest, meanest critters I have ever met. Catching them barehanded is just asking to lose a finger or two.
Here's a video of the Turtle Man hunting:
Note at 2:15 he talks about luring snapping turtles in to bite his fingers. AT 4:20 he catches one. At 4:50 notice how the turtle is trying to bend its neck to bite anything it can get. Then they demonstrate how quickly the little monster strikes.