Supplies spoil - I didn't know that
OK, so spoil isn't a good word to use in the context of some goods like horseshoes. Foodstuffs obviously would spoil due to ageing. Think real world. There is a factory, management clears off on hols for a while and the workers are left unattended and don't know when management is back. The lazy thieving little underpaid average worker will start helping himself to stock left laying around. The answer to "it isn't really spoiling but I don't know what to call it" is PILFERAGE. Yes that is a real word. It means "A recurrent theft of small items of little value"
<edit 5 mins later> I haven't actually seen the message but it should possibly be changed to include "spoilage and pilferage" or "spoiled and pilfered" or "spoiling and pilfering" depending on how that message actually reads.
<Edit somewhat later> OK I stuck a suggestion in the typos and grammar thread