Polpot was the good guy, he was trained by Jesuits to slaughter all the non Roman Catholic Buddhists and turn the country over to the Roman Catholic Elites in the cities and towns.
The Jesuits made him a military that would follow his every order no matter the outcome.
Polpot turned on his Jesuit Masters and eliminated all the Roman Cathllic Elites in the Government, education system, banks, medical system making the country safe for Buddhists.