Pretty sure on the answer here, but there was enough uncertainty in Discord to post here to make things official:
Does Shield of Faith prevent Ricochet from being played at all (by both sides, of course)?
Shield of Faith:
Dudes cannot be aced or discarded during this shootout, except as a casualty for losing the round or due to their owner's card abilities or traits. Reduce your casualties this round by 1.
The cheating player discards their shooter. If your hand is legal, you do not take casualties this round and draw a card.