I don't think I was wearing that object of clothing at the time. It was a shirt that clipped pretty badly with my default skirt so I never exited the outfit function with it on, that's why I deleted it. Not trying to be difficult, just trying to give relevant info.
Then what most likely happened is that you simply did not save your progress when you deleted the item after exiting Outfit. It's easy to replicate.
Unfortunately I do not yet have a patch for it, as my programmer is unavailable at this moment. Luckily it's a very specific bug that people don't easily come across upon :)