Where did I say snakes? I'm talking about pets, the big cuddly thing that follows you about. I'm aware no logs show snake dmg on the boss, and personally I've seen them triggered by the boss, but they don't appear to do anything.
I can still have a look for a log showing pet dmg during the hide phase, but I know most hunters don't go near the melee range of Lei Shi during hide and it's only by coincidence of the hide location being where i was stood that I even noticed it - so it might be quite tricky to find