It could be taken as insulting, but it's probably true as well. Very few neurologists in the US would have extensive experience grading CM in cavaliers; most of these specialists would also be happy to allow input from more experienced colleagues.
I suspect the quality difference is actually in the positioning of the head during the scan, rather than neurologist competency.
Thank you for your explanation. I don't understand why they don't all use the same protocol. At least there would be some consistency in results.