American Football Rules IFAF Approved Ruling 6-4-1:IV
IV. A player of Team B, attempting to catch a kick (no fair catch signal), muffs the ball that is then touched by an opponent who was not interfering with the opportunity of the receiver when he was in position to make the catch. RULING: Not interference. In the absence of a fair catch signal, protection against interference with the opportunity to catch a kick ends when any player of Team B muffs the ball. [Cited by 6-4-1-c]