I wouldn't worry so much about hypotheticals.
If your buying a used car, the previous owner could have also thrown a crack pipe under the seat. I use to be a dealer tech, seen a million strange things. We had a used car once we couldn't get the dead fish smell out of, then we found all the dead minnows under the back seat.
Apparently someone's bait bucket spilled and they didn't bother to find all the missing fishees.
It's a what if, and a stretch. If it does happen, you sit down with the Service Manager and reasonable people can ussually work things like this out.