Think you missed out some of the key questions, why were bone fragments of the victim found in the quarry?? Also how did he smear blood in the car but not leave a finger print (the DNA found from sweaty hands also without leaving prints) and why would he put the victim in the car to move her a few yards to burn her? There was also the differing approaches to the 2 trials, in Steven's case they said the murder happened in the garage (despite there being no blood splatter and the only DNA bar the bullet being Steven's, although how Steven can explain how that bullet was fired by the gun they found in his bedroom was washed over in the documentary) but then in Brendan's case they were happy with his confession that it happened in the bedroom. Lenk was a particularly unbelievable and wasnt a credible witness in my eyes, at best misleading at worse down right lying, he'd been questioned days before in Steven's other case, and then was confused about the time he got to the crime scene, this after being ordered to desist, he and Colborn were integral in the key discovery.
I would have wanted answers to those things if I was a juror, however, having read some about some of the bits left out of the documentary, like the additional DNA and bullet, I am not at all convinced he was innocent. Brendan on the other hand, if you remove his 'confession' which he was coerced and without any representation, with there being no physical evidence against, I think I would have found not guilty, as without that confession there is nothing to find him guilty.