[neverdem]

Considering the local doctors had proclaimed our granddaughter free of any ear infection just a couple hours before her ear drums blew out (yep, an infection by golly!), what’s the chance this is because fewer doctors are capable of diagnosing one?

You look at the ear drum with an otoscope. It has a characteristic appearance. Normal looks like a pearl described as a "anterior cone of light." If it looks odd, and the kid has symptoms, any doc should be able to make the diagnosis.

[Smokin' Joe]

If it looks odd, and the kid has symptoms, any doc should be able to make the diagnosis

Agreed. Grandma had the doc 2 to 0, even without an otoscope.