280.00 in an envelope?
Can you post the picture showing damage? Sounds like he may have pilfered the envelope when he saw it was damaged.
I’d surely want him to return everything including the damaged envelope.
He might be lying, or might not. In the event that he is lying, asking for them back might be enough of a deterrent for him to arrest the case. It may also turn out the nothing was damaged at all. In that case, you definitely want the cards back. Any other shady activity and you will want the package and cards back to ascertain whether or not he took advantage of you. In the event that the package really was damaged, it would still be wiser to ask for it back just to be safe.