Norm MacDonald used to rip on Michael Jackson a lot. He was the Weekend Update guy on SNL and eventually was fired to continuing to make jokes about OJ Simpson. He would actually take on celebrities when they were awful and it got him fired.
A child molester (Roman Polanski) won the Oscars Best Director Award in 2003, to a standing ovation, although he wasn't in attendance because if he came back into the US he would have gone to jail. I bet if you dug up the SNL weekend updates from that time there's be nothing about it.
Here is a collection of Norm ripping on Michael Jackson.