Well it did work just fine for me. So "doesn't always work" is probably accurate.
They changed the charge after I got there to one I wasn't prepared to disprove (but was no more valid).
Yeah that seems pretty dubious. But if they had actually pulled that on me I'd have responded that I'll need time to prepare a new defense against these new charges; and time to consult my lawyer.
There's no way they can charge you with a new offense AT YOUR TRIAL and then prosecute you for it immediately like that.
I got a ticket when I crashed a motorbike because the cop that responded thought I deserved punishment for his trouble of showing up. Speeding (30 in a 55,
Speeding is more than just exceeding the posted limit. Driving too fast to maintain safe control of the vehicle is illegal. You lost control of your vehicle. That the issue was your own inexperience more than the weather or the condition of the road doesn't really matter.
with lots of witnesses), and passing in a no-passing zone, because I crossed the center line when I crashed.
Crossing the center line (when not part of a legal passing maneuver is also illegal.)
You can of course legitimately argue that those aren't the best offenses to charge you under; and you might even be right. But face facts -- you were driving and you crashed and you were 100% responsible for the crash -- its pretty hard to do that and not run afoul of the motor vehicle acts in some way.
so he flat made-up tickets unrelated to what I actually did
I think the tickets, while perhaps not ideal, were reasonable choices.
to make sure I got punished for bothering him on a Saturday Afternoon.
Perhaps; perhaps not. I don't know what happened, what the damage / injury level was. It certainly could have been him just being a dick -- or it could be that he felt you were a legitimate danger to yourself and to the public and wanted to send you that message.