Boy must have been so drugged out that he forgot he was in Texas. Woman needs better reflexes, however.
Thanks for the softball question.
1. NEVER fire a warning shot.
If you are in a position where you need to shoot, shoot to end the threat.
2. Don't wait until your companion has been beaten to the point where s/he is lying motionless on the floor. You shouldn't get even, you should stop the threat in time to do some good.
Anything else you need to know? Perhaps you should take a concealed carry class. You appear to be in a position to learn a lot. Or pay a competent lawyer for advice.
Also, the girlfriend probably didn’t want to take the shot while her man was being strangled. The article states that only after she saw her boyfriend’s “lifeless” body did she shoot to kill. Lady did good.