Halon on submarines??

The BBC reported the accident with updates today.

Halon is normally used around highly valuable computer, telecommunication, switching equipment and in the engine rooms of ships. Its advantages as a fire extinguishing agent was that it had lower toxicity other chemicals and that since it was a covalently bonded, it did not form conductive ions which made it usable on electrical equipment. Production has been banned in most countries since 1994 as part of the Montreal Protocol on ozone depleting substances. We use it here at the nuclear plant in computer, switchgear and relay rooms. The commercially available systems that we use consist of storage tanks, actuation control systems, alarms/lights (gives you the 30 second evacuation warning) and each subsystem has a manual override capability. The purpose of the override is so that if the discharge is inadvertent (unsanctioned as the Russians say) it can be stopped, however, it is a spring return mechanism designed such that once released, the 30 second timer starts again. When concentration reaches about five percent the atmosphere will not support human life and breathing apparatuses are required.
I have also found through my training as a fire/hazmat responder here that the face pieces of the EAB’s on the boat would most likely sealed fairly poorly in the event of an actual emergency (you’d stay alive but use a lot of air).
I can see using an agent like this in a building, if the warning goes off, run out the door. I can even understand using it on a surface ship, once more if the warning goes off, run out the door. I can not understand using a system like this on a submarine, even if it were “overengineered” like a lot of the things on boats. Additionally, having an automated system like this on a boat doesn’t pass the “good engineering practice” or common cense test.
My prayers are with the dead, crew, and families of the NERPA.