Who knows but at least you were refunded and left whole.
I do wonder sometimes what a customer would do if they were sent a higher priced item by mistake and how readily they would contact the seller to let them know, not implying anything or trying to twist the thread.
I just worry more about being scammed and losing my payment or having payment data compromised in some way. Neither are hassles I relish. Being told an item is not available, while it may be disappointing, is not something I fret over as long as my payment is refunded.