Comey admitted that Hillary did the things that are spelled out in part (a) of the statute. That is beyond debate.
Because she did those things, as the FBI investigation showed, the statute applies - court ruling or no.
In reality, yes. In law, no.
It's a statute. You have to apply it. That invokes a judicial proceeding. The conviction - not just the accusation - has to be produced, or that particular statute can't be applied, by definition, because that statute references a conviction in its own definition of itself. Hillary's defense would be that simple: she rejects Comey's "opinion."