There's a very simple way for him to prove that he's genuinely relinquished control, and that this isn't simply a bit of deckchair moving in order to keep the torches and pitchforks at bay.
1. Retract the rejection of the Lapping deal, contact Andrew Lapping and tell him his offer is still under consideration, and that it will now be dealt with by whoever is now running the club.
2. Advise the "billionaire's" agent/mate/translator/personal trainer (or whatever) that Nixon is no longer their contact, and that all future "negotiations" will be handled by, once again, whoever is now running the club.
If both of these things happen, and are proven to - and confirmed by - a genuinely independent observer, then I'll accept that he's really gone.
Until then, as far as I'm concerned, he's about as much "gone" as Pattison is.
i. e., not very.