Based upon what Matt has given us in terms of how the event unfolded, I will say that Matt was the highest medical authority on the scene.

Unless the other medic was on duty or since both were off duty, Matt was outside his jurisdiction and the other medic was within his jurisdiction, Matt had, by his action assumed responsibility and authority of patient care. His initiation of treatment (c-spine stabilization) was in keeping with the standard of care, his treatment should have continued until the EMS units dispatched arrived and assumed patient care.

The LEO, unless he was also a paramedic should have concerned himself with control of the accident scene and not patient care, since Matt identified himself as a paramedic.

An accident scene can be utter chaos, it is up to the highest ranking EMS or Fire official to assume control of the scene, until relived by a superior or higher trained individual. In Maryland, by state law, fire line-officers, not EMS officers are responsible for incident command of the accident scene; EMS personnel are responsible for patient care.

Pete