OJ was getting ripped long before the civil trial.
I'm not. A civil suit over calling Rittenhouse a murderer wouldn't survive summary judgment. It is undisputed that he committed an act of homicide. That is a matter of fact. A defamation claim has to argue that a statement is false. That a killing was self defense or murder is a matter of law, not fact. Scores of people have called George Zimmerman a murderer and he'd never win a suit against any of them.
An acquittal has never, in the history of American jurisprudence, precluded free speech. How many times have we heard prosecutors publicly say "the jury got it wrong," following an acquittal? By your logic they have all committed slander. The law does not say that an aquittal is proof that no crime was committed. An acquittal simply means that the state failed to carry its burden of proof. No jury has ever found a defendant "innocent."