The PM continues to take a strong view that his request to the Cabinet Secretary to look into the emails and see whether they changed his initial judgment was the right request at the time. There is nothing in the report which alters this view.
The Cabinet Secretary's advice was very clear the emails were unreliable and should not be taken into account. The PM concluded Andrew Mitchell should stay in post. The Cabinet Secretary's review did not in any way lead to Andrew Mitchell's departure.
It would also have been entirely inappropriate for the Cabinet Secretary to conduct a freelance private investigation into the veracity of the police.