I don't know your examiners exact board certifications (you can search ABIM & AEM boards) but most Peds EM fellowships require prior training in a three-year residency in either General Pediatrics (Peds) or Emergency Medicine (EM). So, the providers background should be sufficient to examine that common aging disease process.
But hey...if you really don't like how your exam went down, read the following.
Take the time to read this VLB blog on this very topic
"... under the “presumption of regularity”, VA is presumed to have chosen the best medical practitioner for the job. "
You CAN OBJECT to the provider and he lists how to do this in 1-5 of this blog post.
For psych exams for example, " Board certified psychiatrists and licensed psychologists have the requisite professional qualifications to conduct compensation and pension examinations for PTSD. Psychiatric residents and psychology interns are also qualified to perform these examinations, under close supervision of attending psychiatrists or psychologists.."
A TBI example that just popped up in the news is below.
"VA just funded a research study now being used to support lowering credentialing requirements for examiners diagnosing traumatic brain injury (TBI).
The agency funded a research study performed by the organization formerly called NIH, now called
National Academies of Sciences, Engineering, and Medicine (NASEM), to evaluate diagnostic requirements for TBI.
The congressionally chartered research organization evaluated whether the agency should still require that only one of four specialties diagnose the condition – a neurologist, neurosurgeon, physiatrist, or psychiatrist. The 200 plus page report argues that training and experience, “not necessarily the specialty,” is what makes a clinician capable of accurately diagnosing TBI."
TBI study for VA exams