But, the CORRECT call. It sucks, but when a guy calls for a fair catch, you have to let him make a catch. Here is what I wrote on a message board I have with close friends.
Fair Catch means you have a chance to catch the ball without any interference.
If a receiver juggles a pass and catches it...its still a CATCH.
So, yes, you have to wait for the ball to hit the ground. At that point its a free ball. The receiving team can't advance it, and since its a muff, the kicking team also can't advance it.