the BC just does that. there are a couple of little balls at the main stock at each node. i gave a couple of moms to friends that had those and they freaked out. ive done 3 runs with the BC and never had one seed but see those balls the whole way through. they contain no pollen or seed. youre good to go. ive only had a hermi once and that was OG from a looser clone guy. as far as i know a hermi seeds without pollen and there for there is no y chromosome, ie, no pollen sacks just female seed. but yes those seeds will produce hermi plants.
hope that helps.
also, my BC is one of the easiest grows ever and my best yielder ever.