Some insecticides react harshly when they are accidentially applied to a plant and the plant is young. was it sunny? There are some insecticides that hurt new plant tissue when applied when its hot or super sunny. Maybe the plant had been having an unnoticible problem for a while and by chance...
Im not accusing but it quite simply could be just plain bad genetics. I have a few plants that have angry looking leaves and that is just what they do genetically.
I'm new to this site but i'm not new to growing. I've got hermies and I love them they are a great source for good seeds and since my strains are bomb I love my seeds as much as the bud. Growing is a unique deal and everyone has their own techniques and secrets. I am not bragging , just filling...