Planetary atmosphere story time:

In the early 1980s carbon monoxide was discovered in Titan’s atmosphere. From its discovery until 2008. Chemistry models couldn’t explain why

There were many different theories but nothing fit all the different pieces of evidence and constraints that existed

Turns out we were missing a key piece of information: Enceladus is shooting water into the Saturn system and some of it ends up in Titan’s atmosphere, which wasn’t included in the chemistry models because we didn’t know about it

The less you know about an atmosphere, the harder it is to use a model to draw conclusions about it and the more careful you have to be about how you use it.

Anyway that’s the story.

As an addendum, as a general rule the more dangerous a molecule is to work with in the lab, the less likely we are to have all the data required for atmospheric modeling and data analysis.