As Paul Graham argued in his famous essay What You Can't Say, heresies are things which are not obviously false so they might as well be true.
What would people perceive as lies and be triggered by that? I argue that happens when you face a rival discourse which uses the same facts set but lays them out differently, and contrary to your own beliefs.
For example, take the reactions to the statement that "Russia has liberated Lisichansk". I think it would look like a blatant lie to a Western reader. But why? It's apparent that Russian flag is currently flying other that city. It's also quite easy to prove there are likely some people, an unknown number of them, out of the city's 100,000 population, who feel liberated by the fact that fighting has mostly ceased and they are now on the Russian side of the war zone.
But, you would say, isn't Ukraine a sovereign country who ought to be legitimately controlling this city? Aren't Ukrainians as a whole supposed to be relentlessly resisting and being loyal to their state? And by the way, isn't it spelled Lysychans'k?
The fact set is exactly the same as if the news piece came from a familiar Western source and used "fell and now occupied by Russia" instead. But the discourse (which is really neither true or false) is different. And the facts are cherry-picked from that set in a different, offensive way.
Other than that, people seem to be really offended by existence of adversarial war propaganda. They don't mind allied war propaganda and would excuse it for wishful thinking if it boosts the morale on "your" side (bonus points if it manages to hurt the morale of "them"), but of course they see propaganda from the other side as abomination and magnify any real or imaginary falsehoods encountered there.