The ‘bigger issue’ could be the one identified earlier by AndrewR with which I agree: It could be that this highly improbable event is just the consequence of the probabilities never being zero.
There is no such thing as airspace in which the risk of collision between aircraft is zero. There is no such thing as a mistake-free pilot. There is no such thing as a mistake-free ATS. There is no such thing as a continuously perfectly-serviceable aircraft.
Class G airspace is the one in which the probabilities of a mid-air collision are least remote.
Sometimes the occurrence of highly improbable events is not as positive as winning the lottery.