I don't think the lack of a certified instructor, per se, is the cause of the accident. His father was standing too far away with the a camera and the owner of the weapon was not next to the boy. They allowed a 15 y.o. to hand the weapon to the boy and instruct the boy. The owner of the weapon should have been next to the boy. The owner, knowing how the weapon recoils and rises, should have warned the boy and should have been standing ready to grab the barrel if the boy started losing control.
The debate about whether or not there should have been a certified instructor on hand, opens the door to more regulation and restrictions. The new cry from the left will be that there has to be a certified instructor every time a person wants to try a new weapon.