This would be true if the officer “stood his ground” in the administrative sense and shielded himself within the system. He resigned immediately and shed those supports and no sooner than he did so the leadership of the FW police showed no hesitation to denounce and disown him.
I am a terrible cynic. But this will not be anywhere close to an exoneration. His best defence at this point is simply: “I was scared, I fucked up.” And he fucked up by failing to uphold training and procedure. The only way he gets a light treatment is if his attorney(s) manage to put FW police recruitment and training on trial. Even then, he goes to prison for homicide (to what degree will be at the whim of his jury).