I have had had to deal with exactly this situation twice when Chairman of the Society.
1. Society Referee playing for Vets, and gets double yellow - first for repeat offences at ruck and second for handbags.
On the Monday following we convene an emergency Society Disciplinary hearing - me, Hon Secretary, and Discipline Officer (a barrister) + CB Disc Chairman as an observer. We have Refs dismissal report and hear dismissed referee-player's evidence - suitably apologetic, etc.
We suspend him for two weeks immediately (and really p*ss off the Re-appts Sec :biggrin

, plus awaiting the CB Disciplinary Committee at the end of the month, and that if they give a longer sanction, he will serve the difference as an additional suspension from appointments.
He is given a serious dressing down and warned as to his future conduct whether it is appointed as a referee or playing. He is asked to send a letter of apology to his club and opposition club, plus CB Disciplinary Committee. He also sent one to the Society Committee.
Usual County Disciplinary hearing held two weeks later and he gets 3 weeks playing ban, so he gets extra week appointment suspension.
2. Society Referee playing for second XV - lots of questioning and dissent, which after a YC award for persistent ruck offences, leads to further dissent so upograded to RC, and then full-on touchline & post match abuse.
He ceased being a Society Referee the next day (three Committee guys on a phone confernce for 10 minutes having read the RC and abuse forms. He has not been seen since by us, nor his club who banned him for the rest of the season in his absence. The CB County Disciplinary Committee also banned hom for the rest of the season.