Clear Prop
The firefighters don't use Halon, but the bottles in the cargo hold are filled with halon, my point was the fire would have at best been delayed briefly by Halon. Foam or water would put the flames out initially, but the fire will just re-light after you stop.
Immersing Lithium Ion batteries in water is the only way of controlling the situation, you can't stop the runaway but you will control the temperature and prevent nearby objects from catching fire