In Oklahoma, the use of deadly force is authorized in a Citizen's arrest of a known felon whether fleeing or not.
Now, the operative words here is "known felon" which means you (the citizen) have to know that the bad guy has been convicted of a felony in the past. This can be the case ... recognition of prison tats, recognition of a well publicized felony conviction, etc.
As for the assault on the lady, and has been stated in other threads here, age and physical condition of the victim can make an unarmed physical assault a matter of life or death, or grave physical harm, which would (in OK) make the assault a felonious assault rather than a misdemeanor.
I agree that there is not enough info in the article to allow us a good idea of the level of assault. However, The tenor of the statements by the authorities does give us a good idea of the focus of the investigation. And that is definitely cause for discussion.
As for whether or not an attempt to fire was made, it is now his word against the officer. And we know which side the DA is going to come down on. And I know for a fact that not all officers are truthful in what they put in their reports. These guys have a hard job to do.
I have personally been the focus of a PD and a DA that do NOT believe average citizen's need to carry. The DA started out telling my attorney he was considering which of 4 felonies to charge me with. In the end, he was forced to drop all charges because I stood my ground. Within 2 weeks of that, 4 little teenage hoodlims decided for some reason to hang out on my corner lot while waiting for their drugs to be delivered. When we called the cops, they were more interested in hasseling us about calling them than the 4 kids and the dope car the cop pulled up on (which peeled out in front of the cops.)
After that, when I was in a fender-bender, the cop that showed up was surprised that I was laughing and joking with him about the wreck. Excuse me? Just who would have told him I was such a rude individual that he expected to roll up on a knock-down-drag-out??? Hmmm, maybe another cop, because I didn't know him and had basically no other contact with LEO for the previous 20 years I had lived in that town.
We are not in a contest with LEO, but in some regards, we most definitely are. And the local DA has a lot to do with the attitude of LEOs.