They say x, ask for where they heard about x. They say from y news organization, ask the source for y. If they say z, if z is actually an actual document or otherwise, ask them where in z does y claim x is true.
If z is just another news organization, keep going until they provide (or don't provide) an actual document. If they can't procure an actual document, send it yourself. If z is just another video cIip, ask them for the whole video. Provide them the entire video if they can't.
Do not try to antagonize. Just simply ask the questions as if you were trying to understand their point of view, to learn something we might not have heard.
"You can't reason people out of something they were not reasoned into." These people have undergone traumatic brain washing. They didn't evaluate the evidence, consider the source, and come to a reasoned conclusion. They were terrified into thinking they and all those they loved were going to die, unless they did what the authorities said would make them safe. Anyone who contradicted the authorities (their emotional mommy), were the stranger, the enemy: "stranger danger." Reason can't touch that. You can prove it to them absolutely, and they still won't accept it. Our task is to figure out how to overcome that.