I did a little independent digging into the case - I'm not sure he was innocent. I think the IP was underplaying how problematic it is, the multiple items of this woman's stolen property (not just the laptop) that Williams had. And at some points, they mentioned the foreign DNA on the knife without clarifying it was from the prosecutor and an investigator (they seem to have stopped this when a few people called them out on it).
Having said that.
Evidence was still contaminated. Jailhouse snitches still aren't reliable (I don't really have a lot of reason to suspect his girlfriend was lying, though). The PROSECUTOR of the original case was uncomfortable with the DP. This woman's family didn't want the DP. What justice was done here? What value is there in taking his life? Why NOT let him take an Alford plea and be sentenced to LWoP? Contaminated evidence isn't always going to guarantee anyone a new trial, but it SHOULD be more than sufficient to take the DP off the table. And the jury make-up was terrible - clearly inappropriately stacked against the defendant.