Removing a negative number of items from a script, makes the script terminate with an error
If including a line on the form <Container_ID>->RemoveItem <Item_ID> -1 in a script, this will in Vanilla Morrowind remove up to 2^16 instances of this item from the container. It is not flawless, but with MCP installed the encumbrance of the container or actor will be set correctly, which is otherwise a bug associated with this method. Thus, this is in many circumstances a rather efficient way of removing all items with a particular ID kind from the container, so it is likely to be used in mods at least.
Now, if testing this in OpenMW, the script will terminate with an error (tested on the latest nightly). While the same effect can be achieved with a while loop, I do not think it should be expected from mod developers to modify their scripts to account for this bug. Instead, I suggest that OpenMW changes the behaviour of removing a negative number of items to be similar to what is observed in Vanilla, whether an intended feature or not. Instead of limiting the removed items to 65536, I would remove all items with the called ID, though.