Misnomer. The ground can cause a fumble as long as the player doesn't have a non-hand or -foot body part on the ground. For example, if a player's back hits the ground and the ball is jarred loose, it's not a fumble because the player was down. If the player puts a hand down, especially the hand holding the football, and the ball is jarred loose, it's a fumble because the player wasn't down.
It's basically the same thing the Arkansas QB did about 10 years ago late in the game against Tennessee when arky basically had the game wrapped up. Tennessee scored, won the game and eventually won the MNC.
Adrian Peterson also had the same kind of fumble aginst us 2 years ago.
the ball is an extension of the player's hand so it is the same as a player putting his hand on the ground to keep his balance, if no other body part touches the ground then it is a fumble
In a game against us several years ago, one adrian peterson formerly of the university of land thieves currently of the minnesota viqueens, fumbled like that. Or so I am told.
Was almost a mirror image of Brad Smith's fumble when he got wrapped up by Mike Huff in Columbia in 2005. They reviewed that one (for some unknown reason) and ruled that Smith was not down when the ball was laid on the ground.