I would go with they are over watered, if it was nute burn you would see tell tale signs of yellowing/browning, starting at the tips of the leaves.....Don't chop the leaves yet, let the plant recover some, then if any of the leaves are going to die off you will know. I just let them wither a bit and then pluck off.

I have luckily never over-watered so I am basing this on threads that I have read here, but I have over fed and those pics do not look like that.......Good Luck! :jointsmile: