Trauma didn't you say that the Son was on scene and told you to "Do what you can".
If so:
After some research here is what I found out about the Virginia DNR Laws.
12 VAC 5-66-80 under section E. Revocation
"If the Patient is a minor or is otherwise incapable of making an informed decision, the expression of the desire that the patient be resuscitated by the person authorized to consent on the patient's behalf shall so revoke the qualified health care personnel's authority to folow a Durable DNR or other DNR Order."
So if in fact the Son told you to do what or all you can and he was the contact person for the Nursing Home then the DNR is Revoked per the LAW!!
So the medic was still wrong.
Just be careful...was the son a POA?...this is a very murky area.