I was watching a video of Arkansas and Tennessee in 1998. Clint Stoerner fumbles the ball at the end of the game to give the ball to Tennessee. While turning around he lost his balance and started falling to the ground, the ball hit the ground while in his hand and came loose. Should this have been ruled down or a fumble since the ground cannot cause a fumble? Please give a good explanation using NCAA rules, I have provided a link to watch it, the fumble occurs a the the 2:50 mark in the video. Thanks for the help.
YouTube - Stumbled and Fumbled