Green light is not safe during dark hours. That's and excellent example of bro science making a horrible extrapolation from the fact plants want more red and blue, but recent testing by bugbee showed they very well may be more responsive to green wavelengths as far as fucking up flower light schedule.
Never interrupt the dark cycle. There is no reason to do it. Plan ahead better. 13/11 is fine, but don't go less than 11 hours of uninterrupted darkness. It's 100% avoidable and should be.
if you were flashing light at your plants for any period of time during dark hours, you almost certainly caused it to herm. Possibly a coincidence with poor genetics, but light during dark cycle most definitely causes hermies.
Selfed seeds from a natural hermie is a bad idea. Selfed seeds from CS/STS-application or extreme light stress can be okay. The key is the trait to naturally hermie... if that's what causes seeds, the seeds are all trash or at least more likely to be hermie-prone trash seeds. Selfing is a negative because inbreeding significantly impacts the vigorousness of offspring, but not as bad as selfing a hermie-prone plant.