Legal Question? Had a card stolen from me.

Basically, I let another player someone who I thought was a friend borrow a M-X Saber Invoker because he needed one for the local tournament that night. Was like a 25 player thing with Winner Take All. So I let him borrow it. He ended up losing, and like always he left after his first loss throwing a hissy fit.

He apparently sold/traded the Invoker to another player at locals. I confonted the player on the issue and was basically told "sucks for you."

As it is technically still my property and I have 2-3 other players who will back me up that I only let him borrow it, am I in my legal right to just take the card?