The Top Hat instructions say you cannot leave the room until you hand in the exam and the CDECB instructions say that you can leave to use the washroom. Please explain.

The Top Hat platform does not encourage candidates to leave the room.  When a candidate leaves the room that candidate will be flagged by Top Hat.  A proctor will review the flag.  The CDECB does recognize the need for people to get up and use the washroom.  Therefore, proctors will review the flag and when the proctor determines you have left and returned the flag will be cleared.    Remember, the prescribed time of 3.5 hours to complete the examination will continue to move forward while you are out of the room.