The Cup Is Definitely Not Half Full

(While working my zone, I notice a [Coffee Place] cup left on one of the displays. There are three people around, so I assume it’s one of theirs and leave. Five minutes later, no one is around and the cup is still there. We’re allowed to leave cups unattended for five minutes before tossing them, so I leave it and come back five minutes later to see it’s still there. At this point, I have to throw it away, so I go over to it for the first time to find it empty. I throw it out. Twenty minutes later I overhear this:)

Customer: “I left my [Coffee Place] here and now it’s gone!”

Coworker: “I’m sorry, someone must have taken it and drank it or thrown it out.”

Customer: “Why would they do that?”

Coworker: “Probably because no one was near it.”

Customer: “But it was mine!”

Coworker: “I’m sorry, really. I’ll ask around and see if anyone saw it, but there’s nothing I can do about it.”

(The girl leaves and my coworker comes to me.)

Coworker: “Did you throw out a [Coffee Place] cup?”

Me: “Yeah, it was empty. I also let it sit for about ten minutes and no one claimed it.”

Coworker: “Well, she came back for it.”

Me: “I threw it out twenty minutes ago.”

Coworker: *long pause* “It took her thirty minutes to realize she didn’t have her coffee.”