My mother in law's credit cards were picked from her pocket and nearly $10,000 in credit was charged to the two cards in the next 30 mins. They purchased similar items, a great deal of "whatever could be shipped quickly" with a total of $4000 and $6000 (available credit) on each card. They couldn't even be reported by the time the transactions took place.
Warn your client. If this is a similar issue (sounds quite like it) they could take a big loss when the card report finally shows up and they've already shipped out merchandise.