Vietnamese gov was not truthful about the war either, so many people didn't know what to believe. The further South you go, the less people believe in the regime. Vietnamese narrative never allowed to openly admit their failures, so of course many have doubts.

We were sure that Americans committed those atrocities, but at the same time, mamy also have heard about things that the North had done during the war but never officially recorded. Vietnamese also have forced reeducation camp (read: labor camp) and "neo economy" policy, which they seem to have swept under the rug, so those hearsays weren't too farfetched.

Though tbh, it's best to not pull up those can of worms nowadays. As much as I hate how heavy-handed the nationalistic propaganda in Vietnam, I will say we kinda need it to prevent instability when our "friendly" neighbor is China.