(To be precise, the comment about the null thruster was made by the author in a comment on this article, and by a previous article written by the author, which this one references. It is not in the article itself.)
It sounds like you think the author is asserting that the null test article was intended as an experimental control and that its production of thrust is evidence for the null hypothesis.
I read him/her as asserting that the null test article is an experimental apparatus calibration tool, and that the reading of thrust suggests the apparatus is improperly calibrated, so that no results at all can be inferred from the experiment.
There's a difference between "I don't believe X" (which allows for ambivalence) and "I believe not X" (which does not). There's also a difference between "I believe not X" and "I have no doubt of not X".
I was pointing out that there is no dispute or even doubt about the null article's inability to produce thrust (and this would have been a better phrasing). So the question is not "what does the null article's thrust imply about various hypotheses?" It's "what does the apparatus' measurement of thrust from the null article imply about the apparatus?" GP seems to have missed this point.
> "What does the apparatus' measurement of thrust from the null article imply about the apparatus?"
That makes sense, and I think it's a good question. Thanks for clarifying!