Why on earth would you not have told ATC?
Am I missing something?
Surely ATC being in the loop for a situation like this is a must. I am sure they would have considered not letting the aircraft fly over densely populated areas, would have kept other traffic away and directed the aircraft to a remote part of the airfield after landing ....?
Taxiing the aircraft to the gate and then allowing all of the associated ground handling staff to approach it as it was returning for ops reasons is beyond comprehension.....
Total disregard for SOP's I would have thought.