It was well acted, and it is a riveting story. Because I wasn't a lawyer at the time I didn't appreciate what a spectacle it was. The defense was brilliant, and the prosecution bumbling. The main problems with the prosecution's case were: 1) they had OJ try on the gloves, which didn't fit; 2) Mark Fuhrman was a racist and wasn't even really necessary as a witness; 3) Barry Scheck eviscerated the DNA "expert"; 4) the LAPD had (has) a racist history; and 5) Rodney King's case.
Maybe a 5th point is the jury. How the hell did Marcia Clark and Chris Darden not have a more balanced jury? You can't strike a juror or challenge for race, but they could have found other grounds. This case was largely lost during jury selection.
Lots more went into it that this, but these are the main issues.