This seems like a situation that could been fairly easy to resolve, depending on the cloud at his high altitude when he called ATC. We know he reported being on top of cloud but cannot be sure if it was a large swath of good VFR on top conditions or not(it would have been nice for the air to get a pirep from the nearby military jet).
The pilot had decent flight experience at over 1000 hours. He also had options with 1.5 hours fuel stated to ATC(and depending on what power setting he based it on, could have been extended). All that need to have been done was to ask ATC about weather reports at nearby airports. There were airports within 1.5 hours that had very nice weather. A request for vectors would get him to a safe airport.
Even if an unavoidable cloud layer was encountered, I would suggest that it would likely be safer to penetrate IMC in cruise flight rather than what likely turned out to be a descent at a speed closer to the redline.
And even if he ended up out of non-IMC options with low fuel over an airport with an overcast layer combined with a cloud base that was not too low, he could have put his aerobatic plane in a spin and held it there until clear of the clouds, then recovered.