The cop shouldn't have used his taser against a car (I have no idea what he wanted to achieve with that).

But honestly stating that "he refused to help the man" while seeing those flames and the location? Several possibilities could be true:

• The guy died when the fire started (which seems logical, otherwise he would've come out in flames. Car doors are designed for these situations)

• The guy didn't die when the fire started and he still was too stubborn too come out.

• The guy didn't die when the fire started, the policeman got frightened for his life (as a normal man would be). The guy couldn't come out for some strange reason.

• The guy was unconscious in the car from the beginning, which stopped him from coming out when the flames started. (Doesn't explain the cop's reaction).