Class G you are on your tod see and avoid only.
ATZ which it happened in has different rules but the main ones as always is see and avoid and don't crash into the ground.
As the old tongue in cheek goes if you always presume they are out to kill you, you won't go far wrong.
The rules have been designed so it will always fall back to the pilots responsability. And although its hard for the familys to understand this fact and I have every sympathy for them. Most pilots will understand that its a "there by the grace of god go I" accident.