There are at least two instances where aggro reset does not work properly. Sol Glorificus, 329 AD and The Castle.
After you have been spotted, caught and transported back to the Time Tomb or Castle Prison, the guards that spottet you are still on your trail.
In Sol Glorificus, 329 AD you can have a guard from across town come running at you as soon as you enter the city again.
In The Castle you can meet your captures right outside the prison floor door again.