Many people broke the law but weren't prosecuted because they didn't go far enough to justify it. This person broke the law and was prosecuted because he went further. Sounds to me like he was, in fact, prosecuted because people didn't like him.
Sure, in a sense they prosecuted him because they didn’t like him, but it’s because he went too far. It’s like prosecuting someone doing 30 over the speed limit but looking the other way when someone does 5 over. Yeah, we don’t like reckless drivers so we prosecute the first guy. But it’s not arbitrary, and it’s not improper.
Not that this is particularly important to your point, but 30 over vs 5 over is usually a different law.
I'd argue that there's a qualitative difference between selective enforcement that involves informal standards that evolve over time (e.g. police ignoring anyone who breaks the speed limit by less than 10MPH) and selective enforcement that involves a law that hasn't been enforced for centuries being pulled out of retirement and aimed at a single individual.
