I am a firm believer in free speech. The cure for bad speech (as the accusation apparently was) is not less bad speech but more good speech.
Fine, but doesn't there have to be consequences when someone just makes shit up about someone else? Especially when it's something that is such a powderkeg in current climate? We don't consider it reasonable that people prove a negative, so you're already on the backfoot if someone decides to start a rumour. With Twitter and Wikipedia, it's very easy for a rumour to get repeated so much it feels like the truth.