But you started with males, so this was not a herm observation, was it? The term autoflower is also a bad one to use here. That implies Ruderalis genetics and a flowering cycle based on time from germination and not light deprivation (or as you claim, being root bound triggering flowering). You may have forced flowering somehow, but it was not an auto flower. What you describe I have never seen in any of my grows. I typically light dep my seedling plants in late May to force flowering in one gallon pots to determine males and females, and then pot up the females and put them out in the GH under long light cycles to re-establish veg growth and bloom normally in the fall. Or if it is a warm spring, I size them up in February and March and set them out in late March to bloom, and let them bloon through June. Then cut off all the bloom and re-veg them and they bloom again normally in the fall. Potting them up or down has never forced any blooming in my experience. I also pull in fall bloom plants and cut off the blooms and re-veg them under lights and then take cuttings and root them. Talk about root pruning? I cut all the roots off that way and root them in a bubble cloner. No bloom forced that way either. In all of these methods, other than force blooming with light dep, they have not bloomed. Save for one strain of Durban that has wild bloom times from landrace seeds that I got from South Africa. I stabilized that with the Dutch Durban that has some skunk in it. That Durban back cross strain that I bred is being sold on some sites in the UK now.OP here (me!) chiming in with yet another observation of males autoflowering when root bound. Of the six Angeldorado males I grew out last summer, I kept two of the best clones and let them go in my veg cabinet. One (the taller, more vigorous one) autflowered in a big way under a 16-hour light cycle when it was rootbound. The exhaust from my veg tent is (was) right next to the inlet to my flower tent. That pollen got everywhere and knocked up everything. So I have lots of new seeds to play with, LOL. The take-away: I've now had two males derived from Angel's Breathe stock autoflower under 16/8 when root bound. It is most definitely a thing.