Below I've linked the original KS thread on the alleged het pied sign.
Whether or not ringers are more likely in het pieds is also open for debate. Could a ringer condition caused by something not related to the pied gene be causing the pied het type belly?
I hatched a much less dramatic ringer last summer that is technically a 25% chance het pied but based on his and his father's bellies I'm pretty sure he was het. Hopefully I was able to talk the lady who bought him as a pet into breeding him some day.
I don't know anything about the sellers and didn't even try to look them up on the site that we can't name here because I didn't have the money to buy this guy but it did strike me as slightly odd that anyone would have a pied female and not breed it to a pied male, even if a breeding loan was needed to do so. Hopefully they had a good explanation for this.
It also got me thinking if I had ever seen a pic of a pied female on eggs. What if some day we run into a mutation which makes one or the other gender infertile in the homozygous state? I'm sure someone can quickly post a pic to eliminate pied from any such suspicion but just one more thing to worry about with each new morph.

Feb 2003 Kingsnake thread on het pied sign