Yet might there not have been an additional underlying factor that threw even more kerosene on this fire? I'm referring to a particular cultural mix of West and East. In this case, the West is the Spanish heritage of machismo (popularly referred to in the Philippines as "guns, goons, and gold") which along with private armies predominates not only in this country but in parts of Latin America as well. The East is the Muslim / Arab tradition in this predominantly Islamic part of the Philippines (the Autonomous Region of Muslim Mindanao), of rido, i.e. clan tribal rivalry, warfare and vengeance. Add to this the devaluation of life of the "other" which is common to both societies along with the hair-trigger amok temperament that prevails here, plus the aforementioned corruption of public officials that is so widespread throughout the nation as a whole, and you have one volatile brew.
In other words, were it not for this particular cocktail of cultural influences, I think that even taking into account that one side was the ruling dynasty in this locale, the power struggle with the victims, the Mangudadatu clan (who ironically are inter-related with the Ampatuans) might have turned out differently. I further believe that when the final historical chapter is written on this tragedy, the blend of violent mores in this locale deserves to be taken into consideration (and this is not to diminish their personal responsibility for their actions) as a contributing ingredient that helped to harden the Amputuans into the sociopaths that they eventually became.