Originally Posted by Rock Chalk
No, you lose that challenge if its not a first down. I gaurantee you that's how that works.
You can only challenge forward progress with respect to a first down. If forward progress does not result in a first down on the challenge, you lose the challenge (even if they move the ball) and lose your time out. The timeout would not have been important but the loss of the challenge may have been.
edit: Rule 3, Section 9, Part C.5
You reference the rule for fair catches.
Rule 15, sec 9, A3 says you can challenge whether a runner is in or out of bounds regardless of first down marker.