I just watched the video, and I think it makes my point. Yes, Walters can 'bring the house down', but as they say in the video, there's no one even close to him, so despite his phenomenal success, the Vegas books still make tons of money, year in and year out.
Walter's has managed to lay his action for many, many years, and I'm sure anyone with his kind of juice would manage to get their action down as well, so I'll stick with my position that the sports books are being irrationally paranoid.