In the Commerce > Commodities > Sell view you can only sell commodities, and when you try you get a confirmation dialog with additional information first. However, in Ship > Sell you can also sell commodities (in addition to the expected ships), but selling them you get no confirmation.

Commodities should not be listed in the ship sell view at all, or if they are, then the sell process should be the same as in the commodities view. The way it currently is surely cannot be working as intended.

PS: There should really be a confirmation for selling ships, too, but that's not a bug, just a suggestion.