I read about Dingle's objections to special relativity and thought I'd check it out, so I bought his book. I shouldn't have. It was a wall-of-text gamma screed that was 10% incoherent physics and 90% indignation at being poorly treated by the scientific community. I was hoping to at least discover some good quotations. The best I found was Max Born telling Dingle that Dingle's book on special relativity was awesome and then a couple of decades later telling him he had fundamental misunderstandings and ought to read a good book on the subject. That was funny. I may be able to use that.

The second dispute began in the late 1950s, following Dingle's retirement and centered on the theory of special relativity.[8] [9] Initially Dingle argued that, contrary to the usual understanding of the famous twin paradox, special relativity did not predict unequal aging of twins, one of whom makes a high-speed voyage and returns to Earth. However, Dingle then came to realize and acknowledge that his understanding of the problem had been mistaken. He then began to argue that special relativity was empirically wrong in its predictions, although experimental evidence showed he was mistaken about this.[10] Ultimately, Dingle re-focused his criticism to claim that special relativity was logically inconsistent, declaring that special relativity "unavoidably requires that A works more slowly than B and B more slowly than A — which it requires no super-intelligence to see is impossible."[11] Hence he asserted that the well-known reciprocity of the Lorentz transformation is self-evidently impossible.[12] As Whitrow explained in his obituary for Dingle, this is not correct, as it rests on Dingle's mistaken assumption that the conflicting ratios of event times used by Dingle are invariants.[1]

That sums it up. Two observers each perceive the other's clocks are running slow; two clocks cannot simultaneously run slower than the other. I get his point about that being a metaphysical impossibility, but I'm fine with it being an apparent difference in perspective from two observers.

One might similarly refute the law of perspective by saying, "Let's stand apart at a distance at which you appear no bigger than my thumb, and I appear no bigger than your thumb. Since we cannot both be smaller than each other's thumb, the laws of perspective are inherently contradictory and in error."

https://en.wikipedia.org/wiki/Herbert_Dingle
https://amzn.to/4eaU8gn The reviews lie.