I believe the alien cow fart theory!

Burps primarily as far as the cows are concerned. Mostly just cow pies are coming out the other end.

So much Astronomy drama!

Would be funny if that failed star was actually an alien megaproject but we think it's a natural explanation that means a planet teeming with ancient life is assumed to be barren like the rest of them.

Is there a name for that, when something very interesting is mistaken for something very uninteresting? Not that a failed star full of biosignature molecules sounds uninteresting, do they have any explanation for that?

Astronomer here, the "life detection" on K2-18b was dimethyl sulfide (DMS) which may be ̶I̶s̶ ̶a̶n̶d̶ ̶r̶e̶m̶a̶i̶n̶s̶ a marker for life. What you get from the James Webb Space Telescope (JWST) is raw data that needs to be treated and calibrated to some extent to be usable in scientific study. This is called data retrieval.

However, the lead scientist on this paper claiming they found DMS basically used his own very specific way to do it and found very very weak signals in that way. Other scientist tried to both reproduce it in the way he did it and also with their ways to retrieve the data, but couldn't find anything. So it turns out, it was simply a non-detection.

Edit: It might be the case that DMS can be produced abiotically (scientific works of this year) as chosensilence pointed out correctly.

My main point is, that the DMS detection itself was a non-detection in this case

John Michael Godier will be disappointed

They're obviously full of plants and algae!

Get Back to me when you find it on a planet other than Earth.

Just about every element comes out of a super nova. By the time it's around a planet, Oxygen has made friends, usually Hydrogen, so it's no longer free molecules.