To answer you last point there, Chugs, I cannot create a full picture of the air control environment on the day, but generally there are a number of measures. I shall just give two GENERIC examples. Close up with a squawking aircraft and tell EVERYONE you can that you have no M4. Now, the battery in question was acting autonomously so I would guess that getting the word through to them to go weapons tight might have taken a while, but we don't know how long before the engagement the failure occured. It is normal for ACOs to have lame duck procedures.
I say again, my examples here are generic and not exhaustive.