I thought this one was strange.
I had my sim (Grimsoul Blackheart) at the park just letting him do whatever he wanted to. He got hungry and went over to the grill and fixed some chicken. After he ate a serving he got up and swiped the remaining chicken. So he basically stole his own food.
I checked his inventory and he had the food and when hovering over it said it was stolen from the Blackheart household.
Wondering what would happen I clicked on the plate in his inventory and selected to return the stolen item. It then vanished and he got the +1 happiness buff for returning a stolen item and also had the energized buff from stealing it the first place.
But he didn't have the food anymore even tho he returned it to himself.