The one big difference: She was a trained and, for all intents and purposes, a veteran officer. 4 years in, you're past being a rookie and you've learned to deal with the adrenaline spike and shock of an encounter. Sure, she hadn't shot someone before, but I'm sure she's dealt with a shooting victim in the prior 4 years with Dallas.
One of the things that is drilled in at the Academy is that if you are ever on-trial . . . "I was trained," "It was my training," or "In training, we" . . . . statements I have not heard from AG throughout. I realize the FOP isn't providing her attorney, but it's so odd not to have her rely on her training and instead answer on the stand as if she's an untrained civilian who has never been exposed to blood. It's mind-boggling.
