Frankly... it is highly unlikely... but I will admit that his story is possible. I mean sure, it would be a TB/DLs wet dream and a deekerish fantasy... but still.
I have seen parents react in such ways towards other things... alcohol and cigarettes for example... they catch you with it... and make you drink/smoke all of them hoping that it will make you sick and you'll learn your lesson.
So maybe... maybe... if your parent was that kind of person... I could see them saying "You wanted the diapers so bad, now wear them!" in hopes of embarassing you enough that you wouldn't want to do it again. I know from hearing enough people on this board that wearing diapers to school or out with friends is a nightmarish concept for many who view this as their little thing to do in their bedroom alone at night.
Honestly I don't think it would make the desire go away... but it would cure you from buying diapers again for a while anyways.
To us it all sounds so fantasy-ish and far fetched that we'd never believe it... and a lot of that was in the way that he presented it... but maybe, just maybe.