The idea that a standard fare is £100 is ludicrous. It's really a fine, disguised as a fare, because they can't admit it is a fine as it would then be illegal.
I am not suggesting this for mainline rail, but it does work on metros where onboard purchasing is prohibited. There it is a fine for fare evaders - although they can't legally call it that. There are signs everywhere warning people "DO NOT ENTER WITHOUT A VALID TICKET!". If the machine at a stop on the metrolink is broken, you contact control via a help point. In this case, Yorkie, a penalty fare (or standard fare) is designed for fare evaders. People without tickets on there know full well what they are doing.
I am afraid at some point you have to lay down the law (or bylaw in this case).
I also find it very hard to believe that penalty fares were introduced with the sole intention of penalising people who made mistakes. That might be reality, but was that their main motivation?
If penalty fares can work effectively in other countries on suburban services, why can't they do here?
Is someone who jumps on for one stop every day in a PF zone without a ticket, but will pay a PF when asked, are they a dodger?
--- old post above --- --- new post below ---
I find it hard to believe that Northern will not charge him 6 times out of 10, Northern guards are always keen to collect revenue in my experience. Anyway PFs won't help in the situation you describe. He admits to deliberately ignoring the guard in order to avoid buying a ticket, so that's an admission of intent to avoid payment. So I would say the solution there is to prosecute.
It really depends on the line (and time) Yorkie. What if this guy is only on for one stop? If the guard is occupied with other things, or their machine is broken yet again, then there is no collection made!
Northern guards do try but a packed 3-car 323 isn't easy to check when you've got the doors to do as well. I also see it quite regularly on my local line, which uses 2-car 142s mainly.