That said, I do think he absolutely deserved to be released, not because he didn't deserve to be locked up in the first place, but because he's clearly been rehabilitated and has done great work during his time in prison. All that considered, ten years seems like a not unreasonable prison sentence for what he did. I hope he'll continue to do good when he's released.
In hindsight, the prosecution probably wished they didn't do that, since they are said to have had overwhelming evidence and proof, and there is even a Wired article about chat logs pertaining to DPR seeking services, but those are the breaks! If you don't do your due diligence, criminals can be let off on a technicality too!
They absolutely do that all the freaking time. Especially when other convictions already result in a long sentence.
Prosecutors have limited bandwidth, and just wasting time adding one more life imprisonment on top of a life imprisonment is not helpful.