I'm a little confused about what questions are being raised, but maybe this will help this discussion. This was from Dr. Vass' forensic report:
So at the time he tested, if I'm reading this correctly, the levels were low compared to what levels it takes to make you dizzy or knock you out, but 'over the top' as compared to what is a normal range for decomp, and as compared to his junk yard control sample of carpet.
As for what the jury should have done, IMO that would be to look at the evidence that was available to them or ask the judge for clarification. They had access to the evidence, with the exception of the can that JA tried to allow them to smell, and could have asked for transcriptions of testimony. I don't have a degree in science either, but I do know how to search whatever info is available to me and to ask questions. This jury's questions were evidently restricted to 'what's for lunch?'