fumble or down

Question
In yesterday's Michigan vs. IOWA game, the Michigan quarterback was rushed.  In his attempt to escape, he first balanced himself by placing the football on the ground. (He had full possession.) After which he lost possession of the ball.   It was ruled a fumble.

What is the rule about "when is a fumble a fumble?"  I thought in college (when a runner cannot advance the ball after being down, that if the runner, in this case the Michigan quarterback, puts the ball on the ground in possession of it, would he not be down and therefore could not fumble it afterwards?  

Further, no part of his body was on the ground.

Answer
Graydon
Thanks for the question, I have had several questions about this game.  Please know I did not see the game I was working a game else where yesterday.  The Big Ten Officiating staff is excellent and well trained.

A Fumble is defined in Rule 2-11-1 as follows: "To fumble the ball is to lose player possession by any act other than passing, kicking or successful handing". In your play [the QB in an attempt to escape, balanced himself by placing the football on the ground, with full possession, after which he lost possession of the ball. It was ruled a fumble]this is a correct ruling.  The ball would be loose and ruled a fumble as describled.

I believe the following YouTube clip shows the play you ask about at 1:12 on the following clip:
http://www.youtube.com/watch?v=K0DndD0UnG8

If the above clip shows the play you ask about at 1:12 then it is clearly a fumble.  The QB looses possession of the ball while scrambling.  Once the grounded defensive player gains possession of the loose ball, the ball is dead in the defender's possession. It is change of possession  1st and 10 for Iowa at the spot where the fumble was recovered.  Yhere is nothing in this play that causes the Michigan QB to be down.  The ball remains alive as the QB scrambles and fumbles the ball.  

Remember, When a fumble is caught or recovered by any inbounds player, the ball continues in play.  However, in your play when a fumble is recovered by the opposing player on the ground, the ball becomes dead and belongs to that team's player.

A live ball becomes a dead ball as provided in the rules, such as:
- When any part of the ball carrier抯 body, except his hand or foot, touches the ground or when the ball carrier is tackled or otherwise falls and loses possession of the ball as he contacts the ground with any part of his body, except his hand or foot.