The (hopefully fixed in 4.3 SP3) Tiered Admin report shows the admin that made an imported change, but not what those changes were.
So when looking through for changes, there is no way to track who may have changed a group/users etc if it was done via an Import.
Daniel R2 Sharp
Kaiser Permanente
10180 SE Sunnyside Road
Clackamas, OR 97015
503.571.4827 (office)
daniel.R2.sharp@kp.org