You misunderstood that scene. It wasn't about Fuhrman admitting he planted evidence by taking the fifth. It was about Cochran taking what Fuhrman WAS guilty of (racism and scumbaggery) and using his insistence to take the fifth about those subjects and map that onto the idea that maybe he planted evidence.

In fact he told her not to bring her jacket, so this wasn't just spur of the moment scumbaggery.

But that didn't prevent you from running your mouth.