I'm not sure what the card had to do with the coin, but it's blatantly obvious what is being done with the coin. I don't think it's a gimmick, just he's really good at catching things. It may be a hooked coin, but that would kind of hurt a bit. Then again I'm the one who drives nails into his skull for a living too.
Though that's a very interesting concept... To have a signed coin visually vanish, and then blister a card, cut the blister, and produce the signed coin from it. Might be something worth playing with.