I imagine AJ didn't have enough proof of his motivation to call it out? Then we have Higgins, from an entirely different agency, allowed to come and go in the sally port all day too. Kelly Dever saw Berkowitz and Higgins huddled together and talking for a weirdly long time. All of them are an enmeshed bunch of white bald dudes wanting to be part of the action, and KD too much of a coward to tell the truth in public. I think she must have believed her interview with the FBI would be confidential, and when she found out she had to testify in front of her peers and the public in open court, she panicked. The one respectful, honest, humble cop out of the whole bunch was Nicholas Barros, who spoke the truth despite going against well-known cops in the system! He is a hero!
MOO
ETA: Another surprise was the Chief Rafferty also in the sally port, shovelling out snow? But staying away from the rear of the vehicle? C'mon!