This is tricky. I know how you feel. I'd have want to rectify the situation too. I had a friend who liked ducks. Her friend stole a council duck sign from the side of the road - it was supposed to warn motorists of ducks on the road - to stop the ducks being run over... and he stole it. She put it in her bedroom. When I said, what about the ducks, she replied that there was another one on the other side of the road, so they'd be OK.
I feel she should have got him to reinstate the sign. She didn't ask him to steal for her. But I can also see how if she'd personally tried to give it back to the council, it could have ended up being a heck of a mess, with charges incurred for the cost of reinstating it to its position. Anyway, point is, people do these things, and then they leave us in a difficult position.