This is strictly my opinion. While it is true that pass will conceal that card that was changed from was nowhere near the top, I feel that maybe unnecessary. I daresay, if you were to use a pass to hide the card to the center (or anywhere really), gambler's cop would be more efficient. If the spectator asks for it, flip the entire deck face up, state that it's not even in the deck anymore, and while handing out the deck, just cop the card and hand out for examination. (this too, i feel like is an overkill)
However, I feel like I should mention that don't run when you are not being chased. Don't try to prove that there is nothing to hide, unless you gave them a reason to believe you have something to hide. (this is a very long way of me saying when the change happened, I put the card on the deck, push off the top card, and do nothing else) So relax, practice, a lot of advices has been provided by everybody, and pick what works best for you. Yep.