It would be nothing to swipe the card twice
right in front of the customer without it being noticed. It happens every day in the real world.
I have seen it done right in front of experienced bar managers, who knew about skimmers, knew a particular employee was using one, were watching the employee at the time...and they still missed it!
In fact, there is one technique with the skimmer which has the
card-holder swipe their own card into the skimmer "for verification."
"...there is no time to run through a skimmer." It takes one second. How many times have you seen someone swipe a card once, and then swipe it again? Did it not read correctly? Or were they really doing something else? Are you sure?
The card number, by itself, is virtually worthless...and has been since the 1980's. But the skimmer captures
ALL of the information on the magnetic stripe, including the security devices encoded there. That's what's valuable to a credit card counterfeiter -- the whole package. Nobody cares about the card number.
With regard to eavesdropping on wireless signals -- if in fact,
DVC uses wireless for those transmissions (which I doubt) -- that would NOT yield the info needed to counterfeit credit cards, which is the whole purpose of the exercise. Eavesdropping is theoretically possible -- as is hacking the resort's computers -- but that's NOT where the money is in credit card fraud.