If the pilot had been permitted to file a flight plan coastal and if he had been given a clearance overhead willy- which was CAVOK - the accident very likely would not have happened.
There were no military aircraft flying at the time .
Could happen again this winter.
I find that military controllers want to facilitate traffic .
However if the law says you can't file a plan over William town if the airspace is active it means the controller can't pre plan the aircraft- so there very likely will be a delay.