What is not clear is if this report was available when he got the job or not. Because "he crashed a plane unde difficult conditions" without additional context

What is not clear is if this report was available when he got the job or not. Because "he crashed a plane unde difficult conditions" without additional context might be fine and then 5 months later the report comes out and it is not fine for him to be the CO of that unit. And, being the military (and this also happens in big orgs as well), the people above him can fire hime from a post without much issues.