Whut but how!?

Perhaps it was like what Cash Shop items do; he took the Nose out of Storage/Duey/whatever, ran as fast as he could to the FM and set up a shop and put it in there before it could actually expire. Sometimes when my Cash Shop items say they're gonna expire, it takes them sometimes up to 3 or more minutes pass the expiration date/time to actually expire.

Otherwise, I have no idea how they did it.

That's kinda impossible, as items are supposed to expire as soon as you take them out. The only other way is to unplug your internet cord and rush to the FM, but you'd never make it in time, plus your item would expire when you close store.

The only reasonable explanation is that the expiration date on those items aren't registering, which seems to be supported by this comment:

Edit: Her's also didn't expire or anything when her brother transfered it to his new wind archer and stuff.

Now to figure out how to make the expiration date inactivated...