[panda-giddiness]

> expert witnesses are just a concession the law has to make to get anywhere.

I'm not sure why you don't think that applies here? Only a slim fraction of the population is knowledgeable enough to grok the methodology of EHT.

I mean, if an appeal to authority were as you defined it, then engineers would be making an appeal to authority when they invoke Newton's laws (after all, they haven't derived them), biologists would be making an appeal to authority when they write python code (after all, they didn't write the python compiler), and so forth. Trusting that specialists can do their jobs isn't a logical fallacy – it's a type of inductive reasoning and, critically, a type of reasoning essential for the modern world to function.