Its funny, I watched that with Joey and we both came away with very different impressions. Neither of us had any prior knowledge of the case.
Joey came away thinking that Adnan was definitely guilty and that Jay's story added up when you took into account that he was selling a lot of weed at the time and so, of course his story changed over time -- at first he was trying to hide that from the cops, but when it became clear they didn't care about that in wake of a murder he complied.
On the other hand, I took that same information and went, 'yup, I could totally see the cops, especially Baltimore police, using the weed charges as a way of blackmailing Jay into testifying exactly how they wanted him to." The bit from his interview where the cops go like 'so where did you two bury her?' 'On the side of the road.' 'The side of the road where the big white barriers are?' 'Yeah, exactly, where the barriers are' sounded like he was being fed information.
Either way, quite enjoyed the docu-series; I didn't realize just how close I lived to all that! The crimes took place in Woodlawn, and when I was college I lived right on the line between Catonsville and Woodlawn, a couple miles from the edge of Leakin Park where Hae's body was found.