They don't need to prove all the lines are not spiraling, only to find counterexamples where the lines (spiraling or not) are discontinuous. One counterexample is enough to disprove a theory. Their explanation of exactly how their theory resulted in the evidence we see is easy to understand. A rebuttal would ideally include a similarly detailed explanation and similar experimentation around how fixed cutting points would have produced the same discontinuities.

Thus, in the interest of scientific advancement, I encourage you to, like here, team up with someone who has no horse in the race, and publish an equal or better rebuttal. After all, science can't advance if we just accept what someone says or limit our disagreement to an internet comment.

It's a pretty old article, maybe an unbiased team already has done this!