Depends on the degree of escalation and a tremendous number of other factors, but yes: my understanding is that in Alabama, you do not necessarily need to wait until somebody is obviously trying to kill you to respond with deadly force.

On a personal note, I agree with this. It is unjust to ask people to wait until they're dead to defend themselves, when another person has initiated force that could rapidly become deadly.

It is not uncommon that one pushes another over in anger, and that other is killed. That's not manslaughter, that's murder.

P.S: Be careful mixing up lethal with deadly, or either of those with fatal. There are subtle but important differences.