almost without knowing it, montags hands switch off the safety on the flame thrower aimed at beatty, what does that show about montags state of awareness or consciousness?

I think Montag knew this moment was coming. Captain Beatty was emotionally unhinged and one of them had to die. It does not help that Beatty taunts Montag: who has just lost everything including his wife and house. I think Montag also knew Beatty wanted to die.