Continuity mistake: In the opening chase sequence, while the Nightrider is being chased by two Main Force Patrol, the sun changes in almost every shot.
Continuity mistake: When the Toecutter is talking to Johnny The Boy at the beach, the man behind in the army style overcoat has his hand in and out of his pocket, depending on the angle.
Continuity mistake: When Max first gets in his car at the start, he listens to the chase on the radio and we see the reflection in his sunglasses showing the bonnet of the car, a yellow road sign, and what looks like a white single decker bus/coach (could be the film crew bus). When he pulls away, none of those things are there. He drives down the road and pulls up, waiting for the Nightrider to appear, and we see the same reflection in the close up to his sunglasses again - sign, bus/coach and bonnet, but the road in front is clear.
Continuity mistake: Towards the end of the opening chase, when the police car flips over, just before this you can see the stunt driver in the car and the passenger is missing, not even replaced by a dummy.
Answer: He kills the members of the gang directly involved in the attack on his wife/child, and the one who ordered it.