If it was a hermie, it was probably due to stress. Light schedule getting messed up or temps (heat-stress). There's also a possibility it could be genetic. It usually takes at least 5 weeks for seeds to mature, if they're green instead of a mottled brown they probably aren't viable. I also think if the mother was a hermie there's a good chance the seeds will produce hermies, you'd have to try the seeds to see how likely they were to turn. The bad thing with hermies (and why I pull them) is they produce pollen which can screw up an entire grow. A couple other things, are you sure there are seeds? some strains will get really fat calyx's from resin and look like it has seeds. If you were around any males you can end up with pollen on your clothes or if you ever had males before and didn't wash down your grow area between crops, there could be some pollen lingering. In my opinion, I think if you left a plant grow until it died, it would tend to self-pollinate to keep the species alive, but you would be way past the point of diminishing returns (the trichomes would have been all amber weeks prior). Of course maybe I had to much to smoke and I'm just bouncing random incoherent thoughts around.