According to MediaCorp (2009), “During previous family visits, the JI man had partially closed the cubicle door, then later closed it completely – against protocol which states that the detainee must always be in sight – to test his guard’s reactions.”

Mas Selamat had used omission training to train his guards so that he could escape detention. When the guards did not do anything (omission of response) to his partially closing the cubicle door, Mas Selamat was given reinforcement so he was able to close the cubicle door completely, which gave him the opportunity to escape.