I have personally just experienced this, and after doing a search in the forums I saw that many other players experienced the same thing. With auto-swap now being automatically enabled it can be very easy to accidentally anger a dwarf in dwarftown by swapping spaces with them too much. It's easy not to notice that you've angered the dwarf and then kill them, causing the shopkeeper to become hostile. This recently ruined one of my games and I could imagine it being a source of anger and confusion for new players. I would recommend either having the dwarf resist the swap, make the message that notifies the user that the dwarf is now hostile more noticeable, or just make it so that they won't become hostile when you swap spots with them.