Lets say it violates free speech laws and is liable to be sued and the one who sues is sure to win.
Lets say he sues and wins.
It still doesn't matter. Rumor about the lawsuit and the falsehood of the original content is already old news. And is not as quickly spreading as the original rumor.
The perpetrators of the original rumor win the war to influence, in-spite of free speech protections.
Free speech protections and laws mean nothing and are toothless in face of modern mass media tech.
Compare it to the old days, of the news being said on TV or Radio or in a Newspaper. They too can spread wild rumors but have definite and impactful backlash.
That negative feedback mechanism is lacking in platforms like FB and Whatsapp.
I have seen few people getting beaten up badly and two dying due to mob killing them with law enforcement involved for speaking against "religious stuff" and a politician.
Just a recent thing that got some attention - https://twitter.com/ShefVaidya/status/1251818372343439361?s=...
But I assure you, this happens way more in small towns and villages.
If mob gets triggered by you criticising their cows or government (idk why blind patriotism is so widespread here), what would you do about your free speech if you get killed in the process with no enforcement against those who killed you or imagine a family member?
Honestly I am confused about free speech as well. Is the argument that government didn't stop you from criticising itself, just that the mob happens to kill you for it in public in the presence of the government make sense? Is that free speech?
Also the freedom of speech guarantees are very watered down in comparison with the USA.