I mean, apart from the people literally saying that it's not a coincidence that they didn't give the critique they normally would...
Originally Posted by Knitifine
Spoiler: In which a real scientist does science
First there's the fact that the sample size isn't one, it's forty, because you count every member of both groups when counting a sample size. The group size is one, and also [insert problems with observational studies here], but the sample size is... I mean, I wouldn't trust a scientific study with sample size 40, but I don't have much of a choice and I'm not trying to be massively precise. Second, there's nothing stopping a single result in one group being meaningful for a known prior trend; if it's multiple standard deviations out of line it can easily hit the critical region (assuming p=0.05) on its own. Third, the fact that the change is noticeable with a single result actually implies that the change was a very drastic one. If it weren't then it would only be noticeable after a long time.
But then there's the fact that you're trying to apply scientific rigour to something that was a relatively trivially obvious observation about something that doesn't really merit the scientific method, so I don't know what that says about you.