On the contrary, that comment would be enough to stop me flying QF, if they have F/As who don't understand that water is in fact the recommended way to attack a Li-ion battery fire.
Oh dear, here we go again..
Hope the Hosties at QF now more about it then Dave here.
Off course for cooling that battery you need liquids but to extinguish the flames first, best is halon.
So first the halon, then the water!
https://www.faa.gov/other_visit/avia...FO09013SUP.pdf