The big difference between OJ and Hardy is that OJ had a trial, evidence was presented by both sides, and a jury made their decision................most people that watched the trial think the evidence showed OJ was guilty, but he got off by the jury.
Hardy on the other hand, was never given a trial, was never allowed to put evidence of his own on display, and it never made it to a jury because the DA decided to drop the chargers instead of prosecute.
Now I did watch the OJ trial and I did see the evidence presented by both sides, so I am fairly confident that OJ was guilty (and a civil jury found him guilty later on)............I have not see the evidence in the Hardy case, just media reports and such so I cannot make an intelligent decision about his guilt or innocence. All we know for sure is that an altercation happened that night and its basically a "he said, she said" issue with no physical proof of what happened. The DA decided not to prosecute after the woman disappeared and that was the end of the story. Anything beyond this is just pure speculation.