Indeed, there are no free speech issues involved here. Jones is perfectly free to go on national television tomorrow, if he feels like it, at claim again that the Sandy Hook parents are part of a conspiracy involving crisis actors. No government agent could stop him or criminally sanction him for that. He's free to say it.
But he's also free to take the consequences of his speech. Paying damages in a civil case to compensate the parents for the harm they suffered from his defamation is an ordinary and expected function of democracy.