OP what region are you in?
Some of the older people on the east coast may act in this fashion. My father, for example, makes it a point to never see DOs for any particular sensitive issues/procedures (though he's fine with the fact that in the ER he doesn't have a choice), and he actually understands exactly what they are and the training they go through. He simply thinks that they are less intelligent people due to their weaker academic credentials and therefore does not trust them as much to practice effectively. I do understand and respect his viewpoint, but I would rather he judges a doctor on the basis of his record in practice and patient reviews rather than how he performed academically in undergrad.
But let's be honest -- it's not surprising we are going to have to deal with grossly misinformed patients, on all fronts. As future DOs, I think it's important that we be prepared to be reprimanded by patients, albeit once in a blue moon, simply because of the fact we are DOs. This will usually happen in the aftermath of a negative outcome, as the OP describes.