On May 13th incident:
1. The official estimates are definitely too low to be true, but then again the stories I hear of thousands being killed is also a bit too exaggerated IMHO. I think its closer to a few hundred, and mostly confined to parts of KL.
2. Dr M himself is said to have a hand in orchestrating the incident. He was one of many "ultras" stirring up unrest, and help plot the downfall of Tunku Abdul Rahman, a moderate. After the riots Tunku took full responsibility and retired for good. It is well known that Tunku and Dr M never liked each other.