That specific case was even a bit more nuanced than that. People like to dumb it down and say, "Cops don't even have to know the law!" It wasn't quite that simple.

The law in North Carolina had even been enforced by judges and prosecutors up until that point. If I recall, for many years. Then, an attorney looked closely at the law and realized, due to unclear wording, it's not explicitly clear that it's illegal to drive with only one tail light. They argued, and won.

People don't realize how specific laws have to be, and how often they can be on the books for YEARS before someone makes an argument that something is in fact, not illegal. In my state years ago a criminal case came up where one of the reasons for the initial stop was driving down the shoulder of the road. I think everyone agrees, it's illegal to drive down the shoulder. Well.....it kinda wasn't. The law that referenced improper usage of lanes referenced another section of the code, but that section didn't mention the shoulder, but kind of did lay out the areas of the roadway are between the fog line and center divider. So it was vague, and it didn't EXPLICITLY say you couldn't operate on the shoulder.

I always wondered how many citations got issued, over many many years, before an attorney finally realized the discrepancy and successfully argued it?