A procedural win would be if Musk can convince a court that they don't have jurisdiction (eg, the diver should have sued somewhere else), or that there's some other reason to throw the suit out.
I believe his lawyers were recently advancing the argument that the First Amendment lets you lie about people on twitter, so it doesn't matter if all the twitter claims were lies. If that argument works, that would be a procedural win, aka "it doesn't matter if I did it, because X".
