Are you absolutely sure no late forming male flower shot its load unnoticed?

Pollen can come not only from nearby gardens, but from wild hemp which grows everywhere.

Pollen can even make it indoors on clothes and pets.

A late polinated flower would have pale, non-viable seed at harvest, because the seed wouldn't have the time to mature.

Have either one of you tried to let these "immaculate" seeds mature on the plant?

I've got to respect experience, bonbon, but immaculate seed production would seem to defy the laws of botany.