I well understand the fears these officers had of reporting Hasan as a jihadist.
And if you're going to claim this was the reason, you have to show evidence of that. It wouldn't change accountability, but it would lend credence to your concern. You have to show that US military professionals refused to do their job out of a silly fear, something that would be both cowardly and unprofessional.
some of Hasan’s supervisors and instructors had told colleagues that they repeatedly bent over backward to support and encourage him, because they didn’t have clear evidence that he was unstable, and they worried they might be “discriminating” against Hasan because of his seemingly extremist Islamic beliefs.
Walter Reed Officials Suspected Hasan Was Psychotic The American Catholic
And nothing about them removes responsibility from Hasan. He is guilty of what he did. No one else. But that fact doesn't excuse others from not doing their job either. Everyone is responsible for their own individual actions. And as is common in life, there is often more than one person who holds a specific responsibility in a terrible event.