All cannabis has the ability to go hermie but the normal ones only do it very late in flowering when they haven't been pollinated so try to do it to themselves as a survival trait. Early fem seeds were produced by keeping a female in flower past her due date to make her produce 'nanners. Those were collected and used on other plants to make fem seeds.
Some get a genetic quirk that causes them to do it in early flower and that is an undesirable trait so should not be propagated by growing out seeds from such a union. More prevalent now with all the inbreeding and mixing of strains to produce all the mongrel strains sold these days.
I've been pollen chucking for almost 20 years but I reject seeds from any female that goes hermie. Got a shot glass full of those and all they are good for is tossing around in town for shits and giggles. We used to do that in the Richmond Mall's big plant pots from all the mexi pot seeds we had to clean out before smoking it. Think late 60s.
I'm currently getting into serious breeding to establish some stable lines crossing hi-CBD plants with each other and some of my favorite regular strains. Going to have to make my own sodium thiosulfate and silver nitrate so I can make silver thiosulfate to spray on a female and force her to produce male flowers as some of the strains I have growing now are from clones and/or fem seeds so I don't have a male to get pollen from. I have almost everything I need except aluminum wire to hold the silver coin so I can control how fast it gets reacted in hot nitric acid. Don't want it to boil over.
I've got some studying to do myself to learn more about selecting the right plants to cross and when to inbreed to finally get seeds that grow uniform plants. So many seeds now are sold as F1s which any old pollen chucker can produce but sold for the same outrageous prices as seeds that have been stabilized through breeding multiple generations by people who know what they are doing.