Had a question on a play from tonight.
R12, who gave the signal, looses his handle on the ball (but does not drop it to the ground), while at the time K23 nails him while it is being controlled? Also what if it was attempted to be caught by R20, who didn't give a signal. Kick catch intereference in first, second, both, neither

KCI in the first.
Not on the second. Only a receiver who gives a valid signal is afforded protection. However, there's another thread going at the moment concerning how much time the receiver should be given to catch the ball. See "Obvious(?) Fair Catch Questions"

Nothing in the first...KCI in the 2nd. Once a R player muffs the ball he can then be legally contacted. A receiver is always afforded protection to catch a scrimmage kick. The only difference is he's afforded protection AFTER he catches the ball if he gave a signal. For the player who didn't signal, but caught the ball, a fair catch has not been made but the ball becomes dead. If he's hit it's the official's judgement if the K player could have seen the signal from the teammate of the R player.