> so what chance do individuals have at providing evidence any kind of evidence you would accept? What would that even look like?

As I have often pointed out, proving it is actually fairly easy and pain-free. People who are willing to give up maybe ten minutes of their time and a little effort can use free software tools such as Foobar2000's excellent ABX comparator plugin (installation and usage instructions here) to conduct their own test using their own lossless source files on own their own setup.

The log that results from the test can be saved as .txt and can be verified using Foobar's ABX signature checker to confirm that the results are legitimate. It's not perfect, but it goes a long way to showing that people can actually hear what they claim to hear.

Plus, even more importantly that the result itself, the process of blind testing actually shows to people how small the difference actually is when they don't know which is which and how little it generally matters in the grand scheme of things.