i have had this happen to me too, it sux ballz! only if the light comes on during the night cycle does it ever really fuck up the plants, my plants never got fucked up when the night cycle was a bit too long, all i noticed was more hairs turned red. All they do in the dark is flower, so ur shit prolly just got a bit more mature! Dont worry bout it man, but try to make that the last time it turns off!