The crux is whether the F15 pilot received and acknowledged his restriction to fly not above FL320. If he did, then he failed to comply and directly caused the incident. If he didn't, then the fighter controller didn't ensure separation and is the causal factor.
The other planning screw ups and differences of opinion on airspace status and responsibilities are aggravating factors.
It would have been nice to have the RT transcript to see what took place between the fighter controller and the pilot. It would answer the main question.
In my experience, the USAF are usually pretty good at providing information regarding civil vs military incidents to help investigations. Not sure why they were not forthcoming this time.