As I said on an earlier thread, Horowitz’s job was to protect the establishment, in this case the DOJ bureaucracy.
He obviously subscribes to the #1 Rule of the FBI: Don’t embarrass the Bureau.
The IG has his own rules and procedures to follow.
He is following the rules to a tee and he has been bending over backwards to make sure all peoples rights have been respected - to the point where being scrupulously fair to the guilty has made it unfair to their victims
There is reason for this and it will become apparent down the road.