I would guess that almost every parent has had their child swallow a small object at some point. I know my mom has told stories of all of us kids doing it. Pennies, peach pits, etc.

The first time they freak out and go to the doctor, who tells them to look for it in their kid's poo. The second time they skip freaking out and the doctor step. Parents may not realize magnets are much more dangerous, because magnets, especially strong ones, are unusual objects that we don't have a lot of experience with, and for their size are unusually strong.