Nah, Odo believes in rules and order too much to force others to return their cart when there's no rule saying they need to do so.
He doesn't like it when people leave their carts in random locations, which is why he leaves his very neatly where it's not going to be a danger of rolling into a car or the middle of the lot, but he definitely isn't going to return it himself when it's someone else's job to do so.
Bashir has no idea how carts end up back at the cart return, and between O’Brien and Garak he isn’t likely to learn.