I do disagree, again, to an extent. I wasn't talking about firings.
There is a difference between firing someone, and just giving them new assignments, reassigning their workloads so that they are no longer on the investigation, or that their position is subordinated. No matter how hard you try and avoid it, retaliation in the workforce exists. And, your future and your career are subject to the assignments assigned. The right assignment can make your career or stagnate it.
There is a great deal of hypothesis and judgment used during an investigation. Some leads may be considered, while others discounted.
I think it would be naïve to think that career IO's ignore the political climate. I think every one of them is considering how this investigation will impact their careers.
"Do I present my evidence with conviction", or, "Do I present my evidence as speculative"?
"Do I acknowledge I have a promising lead", or, "Do I state I have a potential lead"?
"Do I aggressively pursue an informant asset", or, "Do I wait for an informant asset to come to me"?
Ultimately... "If I present now, will it be accepted, or, will it be discounted as insufficient?"
Even career officials have to deal with basic workplace politics.