The real "break with tradition" was America and the CIA ousting Prince Sihanouk, who had been fighting militant communists, but was in dialog with the non-militant Cambodian left. A puppet Lon Nol was put at the helm, and the US then invaded eastern Cambodia (and shot Kent State students protesting that invasion) and carpet bombed the Cambodian countryside. This is what began the destabilization of Cambodia. Prince Sihanouk in exile allied with anyone against Lon Nol, which included the communists, and he supported the Cambodian People's National Liberation Armed Forces, which liberated Phnom Penh in the spring of 1975, right around the same time Saigon was liberated from western colonialism.
The implementation of the leftist utopian visions that torture and murder and silence and "re-educate" millions and send millions more desperate refugees fleeing out to die at sea in little, overloaded boats trying to escape is not usually described as "liberation" by those, such as my family and many friends, who managed to survive these visionaries.
