Glad somebody bumped this thread, I was about to start one about this same topic a couple days ago but it slipped my mind. Anyway, it seems to me that a lot of people think if you breath the wrong way on a plant it will cause it to go hermie and from some of the advice people give around here, can you really blame them for thinking that? The fact of the matter is plants and specifically cannabis can take A LOT of abuse/stress before they start showing really negative effects such as hermitization. Like the OP said, a plant that goes hermie most likely did so because it was already genetically predisposed to go that way OR there was a major leak in the dark period FOR AN EXTENDED AMOUNT OF TIME. Aside from those two factors you have to really manhandle your plant(s) to affect the kinds of stress needed to change its sex from female to male. First and foremost a plant's natural environment is outdoors in nature not in peoples houses growing under HID lights. Think about the kinds of fluctuations that occur in our environment, from droughts to floods, high humidity, low humidity, bugs, animals, all kinds of things that can potentially interact with them in a negative way and yet they continue to thrive and grow just like every other thing that is outside with no problems. Because you pruned too many leaves off or overwatered your girls once or twice is just a drop in the bucket to the amount of stress these plants can take in their lifetimes, so I think people, especially new growers should not worry so much about turing their girls into hermies. The bottom line is plants are like little supermen/women that can take a whole lot before you really hurt them badly.