Taking literally the first atrocity you list:

> The massacre at Huế came under increasing press scrutiny later, when press reports alleged that South Vietnamese "revenge squads" had also been at work in the aftermath of the battle, searching out and executing citizens that had supported the communist occupation.[10][11]

This feels like the classic 'barrage of bullshit' strategy, where a load of dubious claims are thrown out in the knowledge that it's near impossible to refute them all, and refuting part of them will come across as "well, this one might be contested, but look at all the others!".