[vintermann]

They test specific prompts with temperature 0. It is of course possible that all their tests prompts were lucky, but still then, shouldn't you see an immediate drop followed by a flat or increasing line?

Also, from what I understand from the article, it's not a difficult task but an easily machine checkable one, i.e. whether the output conforms to a specific format.

[Spivak]

If it was random luck, wouldn't you expect about half the answers to be better? Assuming the OP isn't lying I don't think there's much room for luck when you get all the questions wrong on a T/F test.

[lostmsu]

With T=0 on the same model you should get the same exact output text. If they are not getting it, other environmental factors invalidate the test result.