I would say that have someone call it in. I mean there are more then one fire/rescue/ems department in that area I hope. If you stop that patient you have in the ambulance is going to have that risk of dying.
If you're working them as a code, they're already dead.
Just because you're driving code 3 does not mean that you are free or exempt from all traffic laws. If you reread the original scenario, you're struck by a vehicle that "who didn't care to yield at a busy intersection". What this tells me is that the other vehicle had the right of way except that you were running lights and sirens. Since every law about driving with lights and sirens states (in one way or another) that you must exercise due care and regard for others while driving in emergency mode, the law is going to assume that it is your fault for causing the accident.
You also have a legal responsibility to stop and remain at the scene of the accident. If you leave the scene, here are some things that could, probably would, and definitely should happen to you:
1) Lose your driver's license
2) Face criminal charges for leaving the scene
3) Civil liability - prepare to hand over ALL of your personal property
4) Agency liability - they're going to be cutting a big fat check, and their insurance will be looking for somebody to pay the bill
5) Loss of EMT cert - You may or may not (depending upon your state) have a legal requirement to stop and render aid, aka Duty to Act. Your state Dept. of Health would probably take a dim view of this incident if you left the scene, regardless of whether or not you had a duty to act, because you still broke the law by leaving the scene.
6) Increased insurance premiums for your personal auto insurance.