The most important point is the one upon which Justin and I appear to be diametrically opposed, namely the question of the cost of prosecution.
Indeed, if the headmaster could be relied upon to plead guilty to magistrates, a person of moderate means might have been able and willing to fund the prosecution.
However, had the headmaster elected for trial by jury, the private prosecutor would have been obliged immediately to employ a solicitor and a barrister to prosecute the case and no normal 21-year-old has that sort of money – and it is for that very reason that any competent lawyer would have advised the headmaster to elect for jury trial.
The case would have ended with that election.