Sorry did I miss something, you stated this was a productive discussion.
Absoulutes in EMS are rare. Decisions are made on a case by case basis.
If it benefits the patient for a family member to ride in the patient compartment they do, child or senile adult. We have seat belts there too.
There is alot more gray then black and white in EMS, your decisions should reflect that.
As far as making decisions on the fear of litigation. I dont. I base decisions on what is in the best intrest of my patients.