How to reproduce (in case the video does not work)
(Optional) Fill your inventory with items that are not owned or stolen but leave an empty square
Equip a rucksack in your backpack slot
Go to any shelf and either click the take all button or hold click. Items that don't fit in your inventory automatically go into the rucksack. However, it is still labelled as an empty rucksack.
Trow out the items that are owned in your inventory but keep the ones in your rucksack
Move the rucksack into your inventory. Because the game thinks it's an empty rucksack it will allow it
Walk out of O-Market with your ill-gotten goods.
Some oddities are that the texture for all the items is that of the bag of mushrooms and the stolen icon will appear despite it only being owned (most likely related to #2440). If the player has a dishwasher they can convert the items and sell them.
https://drive.google.com/file/d/1LfsfQlkCFFCDlLp_ddnrZhG3J09AZkVS/view?usp=sharing (Ignore the first two failed attempts)
How to reproduce (in case the video does not work)
Some oddities are that the texture for all the items is that of the bag of mushrooms and the stolen icon will appear despite it only being owned (most likely related to #2440). If the player has a dishwasher they can convert the items and sell them.