As far as "gobbling the card" is concerned, their FAQ states that they can only be used with "dip" ATMs, which may also address the button pushing issue.

EDIT: More details from the FAQ:

Q. Can someone accidentally change which card is selected on my Coin?

A. We’ve designed the button to toggle cards in a way that makes it difficult to trigger a "press" unintentionally. Dropping a Coin, holding a Coin, sitting on a Coin, or putting the Coin in a check presenter at a restaurant will not inadvertently toggle the card that is selected.