Who decides if something is proven false? Who is charge of whats true and whats false?
When it comes to libel and slander, courts get to decide.
You say something about me and I feel it's false and damaged me, I can sue you. It's then on me to prove to the court you lied.
If I were a Sandy Hook parent whose kid were killed, I might show my 20 years of employment records to prove I am not a paid actor, along with my childs birth certificate and coroners report to prove he was in fact real, and did in fact die by gunshot wound to the head. I might get further corroboration from the people that picked up his body at Sandy Hook and took him to the morgue.
The courts would take that into consideration and then give you the opportunity to question the veracity of my employers, the hospital that issued my child's birth certificate, and the coroner that did the autopsy.
And it does not always work. The courts don't always get it right and money really means a lot. Lance Armstrong is a perfect example of this. A lot of media outlets alleged he was taking PED's and had what they thought was proof. But then Lance sued the fuck out of all of them. At that point, it was on Lance to
prove they were lying.
How could Lance prove they were lying when they were in fact telling the truth? Well...at the time..... Lance had better proof he wasn't cheating than they had he was. Even though he was cheating, there were no positive tests to prove it. But there were negative tests Lance could use as proof he wasn't cheating. Faced with that, along with the circumstantial nature of their own proof, most of those folks chose to settle with Lance. But when conclusive proof did come out later, Lance had to give it all back to them and then some.
So perhaps you can take comfort in the possibility that once Alex gets flayed alive, if it does turn out those kids didn't die and were paid actors, he can always try and claw the money back.