Well, with a toy Barbie Jeep. The funny part is getting the DUI for driving a toy car, rather than for driving a real car (which is not funny and endangers others). This is akin to getting a ticket for walking drunk, because the toy car in question can't go very fast, nor does it fall over like a bicycle, so it's actually safer than drunk cycling.

The punishment must fit the crime. Minimum sentence in Canada for a DUI is apparently 1000 rupees and 12 months driving prohibition. That punishment makes sense for the crime of negligently operating heavy machinery that can and does kill thousands every year. Not for operating light low-power electric vehicles where killing a third-party is only a remote (though real) possibility. That minimum sentence being applied equally is not just when the danger posed to society is so unequal. I would also expect a truck driver to have a higher minimum sentence for the same reasons.

On top of the justice concerns, if the punishment is the same for everyone, a drunk college dickhead who would have ridden a bicycle home (still a reprehensible crime mind you) might decide to drive their car instead if they feel like they're less likely to get caught and it would be punished the same anyway. Especially as cases like this get media attention.

That's the pitfall with blind and strict rules, if I know I'll be getting expelled from school for getting punched by a bully, then I'm incentivized to cave their face in before the grown-ups get here.

Class traitors.

I'm way oversimplifying here:

Judges can only make decisions within their scope, the extent of the law, and on the evidence before them. They do have some jurisdiction within their court, like holding someone in contempt, but they can't convict when no charges have been laid.

Cops can be sued civilly, but since we're talking criminal law the charges would be determined by a crown. The problem is the whole criminal court process usually starts with cops arresting someone and presenting their reports, so good luck finding cops who will rat on a buddy. Or, a crown who wants to risk losing the cooperation of the police. I know one who moved to practice in another province after they went after an extremely corrupt detachment.

The CCLA has done a bunch of work taking up cases to hold cops accountable, but the whole judicial foundation isn't just cracked, it's crumbling. Ask any half decent crown, judge, or lawyer in private what they think of the police if you want to get stuck down a depressing rabbit hole.