[cagataygurturk]

I feel your friend little bit exaggerated the situation or simply had bad luck.

The staff of the doctor you usually go knows you and don‘t ask your statuary health insurance card upon each visit. They have it in your file.

Worst case you present a paper you download from your insurance provider‘s website.

As a last resort, you declare you are privately insured and you walk out. They send the invoice to home and you send it to your insurer or pay from your pocket. A simple GP visit does not cost more than 40-50 Euros.

People are helpful. Maybe the staff of their doctor was not that day.