This is what I heard from my father and uncles over the years. Mahmood was flying his plane and saw a smuggling operation. He radioed the police but they were slow to respond. He landed the plane and went to the smuggling site. The smuggler tried to run away and Mahmood shot him, killing the guy.When the police finally arrived at the scene, got one dead man and Mahmood waiting . He was charged with murder and was convicted. The Mahkota title went to his younger brother. Before his father died, Mahmood was given a new title..Raja Muda.
After May 13, many Chinese lorry drivers were roughed up and beaten, by Malays troops manning roadblocks on Johor roads. The drivers complained to Mahmood. He went and investigated, accompanied by members of the Johor Regiment and some lorry drivers.When he saw what happened at a roadblock,he had the federal troops disarmed by Johor regiment troops.He then told the drivers , tit for tat.Mahmood asked his father to have all federal troops out of Johor
Finally, why Johor was spared of may13 riot. Mahmood told the Malay penghulus and Chinese and Indian community leaders to control their people emotion.If the leaders can't control the people , step down and let others do the the job.If any riot broke out, he would held the community leaders responsible and he would personally shot(executed???) in front of their people.