Most asteroids have slowed to terminal velocity by the time they impact. It’s not nothing, but it’s mostly going to be relevant to physical processes and not chemical ones.
You might consider that scientists advanced enough in their field to be launching missions to retrieve dust from asteroids are actually aware of basic facts relevant to their field of study.
You might consider that even concepts like plate tectonics (which frankly are incredibly obvious if one just looks at a map) were considered ridiculous ideas by the most advanced experts in their field at one point. A point not that long ago.
I’m not saying the person you are responding too is right - but appealing to authority on something like this has a pretty bad track record.
Quality of comments massively dropped on the HN. It feels like Facebook now.