[bee_rider]

I think "Be brutally honest about you many assumptions and caveats" at least implies that.

I mean, in an informal setting there's room for an honest person to say "well I did some math and I don't really get it but I think it says...," but I think this article is addressed to software engineers and scientists. Someone representing themself as an engineer or scientists has a professional ethical responsibility to some sort of... I dunno, epistemic honesty, the knowledge of what their expertise covers, and communicating their limitations to laymen.

The person with the A/B test in your example is either a liar because they are misrepresenting what their tool says, or they are a liar because they are misrepresenting their ability to tell you what it says, but either way they are a liar.