If a thief shows his back to the water and uses withdraw INTO (not inside of) the water, it will not go on cooldown and he will be able to use another healing skill when inside of the water.
This is due to the cooldown not activating until the end of the dodge roll. Allowing thieves to use 2 heals in a row.
To recreate, make sure you are on high land so when u roll down that you are sunk into the water. It won’t work if you don’t sink down or if you are on the surface of the water