After accident of Mumbai-Nagpur duronto exp.... SER send few duronto AC and Sleeper hlhb coaches to CR not a full rake ....In return CR send the full HLHB rake to SER.
So, maybe this ICF rake was a compensation to that....or maybe a CBC ICF rake would return back to SER from CR, because CR have many ICF CBC coaches. Ok lets wait for someone who knows the exact reason of it. Some railway Employees can only tell us the correct reason..