alt Hacker NewsNo. It's a description of the result of the maybe underpowered study. the underpowered study did not find evidence. Evidence is absent. Because it is underpowered, it's not evidence that the effect is absent.
The claim is not "two experimental conditions did not differ". The claim is "The data do not show evidence that the experimental conditions did differ".
You say "the underpowered study did not find evidence". Not true, it found quite a bit of evidence - many statistics were presented. There is no absence of evidence. The author wrote about the evidence, presenting P values and other statistics.
Of course the critical part is not the numbers, but what they mean.
So, what does the evidence mean?
The author interprets it to mean that there is no difference. They state this several times:
"46% EXACT PERMUTATION TEST P-VALUE (ONE-SIDED, H₁: CLAUDE MEAN > HISTORICAL)[...] What this p-value tells us is There's nothing unusual about the Claude group."
"74% ONE-SIDED P-VALUE (H₁: CLAUDE MORE LIKELY ABOVE MEDIAN) Fisher's exact test asks: if we split all releases at the historical median (0.74 sev/10c), are these Claude releases significantly buggy than previous releases (more likely to land above the median)? With a p-value of 74%, the answer is a decisive no. "
In an under-powered study, when a P value is above your alpha level cutoff (.05, .01, whatever was chosen) you can't distinguish between "no effect" and "could be an effect, but I didn't see one".