How is he not being the game-disrupting player, in your mind? I ask honestly, because he seems to be lined up squarely against the party, and the "game-disrupting players" seem to be working harmoniously with one another. As always, play what you like
Because his PC is
innocent of the crime he's accused of?
Because the other players
know this?
Because even though the other players know this, they all decide to proceed as if the accused PC is guilty? Even though, at that point, there's been no corroborating evidence either way.
The accused PC is falsely accused of crime, and then finds the rest of the group siding with the NPCs. I'm not sure how anything he does at this point could be considered "disruptive", once the deck's been stacked against his favor like that.
This set-up
could have worked --though I'm not a big fan of the false accusation being of rape-- if it was clear from of the start the PC was innocent. Or if the DM
made it clear when the rest of the party was deciding to side with the townsfolk. Or even a few of players stepped up (with a little constructive metagaming) and sided with the falsely-accused PC.
One falsely-accused PC against an accuser, the law,
and the rest of his party isn't going to end will.
If it were the entire party trying to prove the PC innocence -- perhaps with the added challenge of not destroying his accuser's life (the smart thing to do would be to make the accuser at least partially sympathetic. The only thing worse than a scenario w/a false accusation of rape is one where the false accuser did for no good reason, or merely for the lulz).
Wait... strike that...
if the accused PC was being played as a complete Lothario --ie if it were the player's own agency/chosen characterization that got him into the mess-- then
perhaps it might have worked.
But as it stands, the scenario was a series of compounding mistakes.