Sounds like an extremely stressful situation for this person, not unlike other diagnoses where someone is too often met with skepticism. Migraine and fibromyalgia pain come to mind on that, and the prevailing attitude that one must provide proof via diagnostic testing to be taken seriously is cruel.
I was unaware of this issue until now, also that this condition happens frequently enough to merit it's own acronym (SIRVA).
Unrelated to the case here, I think it's worth mentioning the vaccine in politics angle issue because it suggests the vaccine is the problem, and not the improper injection technique. If technique is the problem, it follows that other injectables must be reported in like manner. It appears that the SIRVA is reported as an "adverse vaccine event".
As we await part 3, I'm hoping proper training is mandatory and that "flu shot" is not without risk, even if you can get one at the mall or a booth at the county fair