SEA @ DEN - pitch to FG K Elam
 

So Denver field goal kicker Jason Elam gets the ball tossed to him by the holder when he sees the right side of the field open for a first down. They subsequently kicked a field goal from ~ 12 yards closer.

When the pitch happens, must the holder lift his knee off the ground? In Canadian ball, it is so: the holder must lift the knee off the ground in order to legally pitch the ball on a fake. If he doesn't, it is dead at the spot of the release fo the ball.

In NF the holder has to raise his knee. In NCAA or NFL he does not.

HS he must.
NCAA not sure.
NFL aplayer is down by contact so there is no reason why a player couldn't do it from the ground AFAIK.

Did the referee throw his flag?

I don't think so. :)

Actually, to better identify that my question was easily answered by my realizing that the NFL plays down by contact, a more appropriate comment from you would be "Did the referee assign forward progress at the holder's location?".

IIRC, the pitch was not forward: I cannot think of any rule in any ruleset where a knee down followed by a pitch is a foul.