Traumatic Servicemembers Group Life Insurance Policy

Here is the issue:
Like it or not I was injured in Iraq, in the back of an MRAP, on a return mission for the commander with his Personal Security Detachment. Ok so what you ask? Well, the Army has an insurance for traumatic events in place that will assist the soldier if they sustain one of a few qualifying injuries or loss of daily activities of living.

Now here's the rub:

“Traumatic” is defined by the policy guidelines as “any injury caused by an external force”. Some examples of this would be an IED explosion, a car accident, or even falling and hitting a knee on the ground."

Traumatic is defined by the  National Library of Medicine as

"A traumatic event is an experience that causes physical, emotional, psychological distress, or harm. It is an event that is perceived and experienced as a threat to one's safety or to the stability of one's world."

The next little phrase that wounded soldiers have to verify are: EXTERNAL Forces.

Introductory physics defines external forces as:

 

the applied force, normal force, tension force, friction force, and air resistance force. 

 

So here we go:

How do you prove external force???