Werewolf Infectious claws from two different werewolves do not work simultaneously. I checked this with my brother last night. When I was casting "Claws of Life" on the target already having DoT from my brother "Claws of Life" - his combat log stopped showing damage from "Claws of Life" and healing from DoT. So that only one of us did full damage, the second only with a light attacks, which was a significant loss of DPS and we could not even kill the last boss in the two dungeons that we tried.

P.S. sorry for my English, its google translate 8)