Even Lemmygrad says there were 300 deaths. I really can't find anyone saying it straight up didn't happen, not even the CPC itself. The closest is saying that the massacre happened outside the square, which seems more of a technicality that both "sides" rely on to pretend the other is making stuff up. Ie, Lemmygrad claiming others know nothing because there was no massacre on the square itself and it all happened outside, while others see that as outright denial.

Lemmygrad also believes it was CIA-backed and turned a pro-Maoist, anti-Dengist protest into an anti-Maoist, anti-Dengist, pro-Liberal Democracy/Capitalist protest, which I would say ultimately doesn't change that protestors were murdered even if that was true.

I think it's helpful to see what people are actually saying, you can better argue it to be an atrocity that way. For example, as above, even if it was steered in a different direction by western forces, it still had popular support and as such was still an unjust escalation of force into massacre.

The massacre is undeniable.