Lots of different defininitions of primary care. For instance, if you are a school using the claim that you produce primary care physicians to get funding then : OBGYN, Psych, Family, IM, Peds, ER, OMM, and Intern/transitional years all count as primary care. If you are really strict, you only count IM, FM, and Peds (cause OB are specialist since they see only one patient population in women). Or you can make up like the doc who grilled you did. Funny thing is my friend who is a FM doc went to their conference last year, and they were saying to not call yourself a 'primary care provider' but rather a family medicine specialist.
Primary care is a buzzword like mindlessness. Lots of people calling different things the same thing, while philosophizing there is a pattern in between. Actually now that I think about it, it makes perfect sense that DO's are involved with primary care more. If we can detect the subtlety of an SBS, surely we can define the pseudoscientific term of 'primary' medicine. Or at the very least, bill/make money off it claiming we have special knowledge.