I'm not convinced about the methods. It looks a lot like p-hacking to me: they have a highly specific hypothesis drawn from a large universe—that dozen or so molecules (§3.1) in their infrared spectrum model they're fitting experimental data against. I don't buy the way they created that hypothesis. The put a handful of highly specific biosignature gases into it, things that were proposed by exobiology theory papers. One very specific hypothesis out of many, and a low likelihood one. And that's the hypothesis they get some borderline ~3σ signals for? Really?
edit: Any chance someone might have the charity to explain why my criticism is so far off-base, according to the HN consensus?
edit: Any chance someone might have the charity to explain why my criticism is so far off-base, according to the HN consensus?