Weed does go hermie.
Typically, you plant seeds, you end up with males and females. The males are killed or otherwise removed and the smokable weed comes from the females. It is not uncommon though for females to get male balls and to skeet out pollen, which would cause seeds to form in the buds.
Not uncommon at all. I've had it happen with my grows. It's good practice to check your ladies for balls and then to either kill the plant or remove the balls. Hermaphrodite marijuana plants = common.
Plants don't become insane and plants don't have different kinds of clothing for different sexes.