some how after, buying it, paying shipping (which is pretty high, and don't they have to pay to send it back?) - it would be rather costly, for something they can then end up in court over.
If someone wants to do that it would be easier to go to a local store and do it. No messing around waiting for the mail or paying to ship it back.
I used to get people that would buy art from the gallery and hang it over the holidays and then return it. Just part of doing business. It was no big deal.
But this is not an issue here. Never even seen it come before.