We'll see what happens after the case works its way through court, but he's already losing several months of wages and the stress of a court battle, which is more than most cops have to go through after shooting someone.
Unfortunately, while it appears the law is on his side based on the facts currently known (Kentucky is a castle doctrine and SYG state), these doctrines are affirmative defenses that must be argued in court. Under most state criminal procedure codes, Mr. Walker can be held until trial (unless freed on bail, or placed under house arrest).
Note that placing someone under house arrest in a conservative state like Kentucky is the judge's way of saying that he expects the defendant to prevail in court and thus won't subject them to the indignities of the prison system, but can't simply release them without bail or restriction due to the nature of the charges.
Both the castle doctrine and stand-your-ground doctrines let people shoot attackers without attempting to flee. One of the big differences is that castle doctrine only applies in your home (but is a very strong defense that is generally acceptable in almost every state), while stand-your-grand would apply outside your home, but is more limited--not every state allows for a stand-your-ground defense. For example, California allows for the castle doctrine but not stand-your-ground, so you would have to reasonably attempt to flee before engaging in deadly force.
Not so long ago, there was a woman arrested for firing a warning shot at her abusive spouse or boyfriend. She was jailed. Unsurprisingly, she was African-American. Women, in general, can't use this defense as often and minorities rarely can.
And few folks can use this against cops - you'd need someone to come to your aid and prove the cop did something wrong.
So Florida's stand your ground law provision had absolutely nothing to do with the case. Plus there's one now pretty old study out there that shows in Florida that blacks successfully used the stand your ground provision of Florida law as part of a self-defense affirmative defense more often than whites. The claim that women are disfavored in claiming self-defense is literally something I've never heard of.
I've seen this happen with fights without weapons involved (both in real life and shows like Live PD), and the charges are always serious if they left and came back, most especially with a weapon.
Isn't that what stand-your-ground law enable people to do?