crashed

[Ron Moore]

It's important to remember that the posted G limits are symmetrical. If he was rolling and pulling, inducing assymetrical G's, the aircraft's G tolerance is greatly reduced. While we won't know until the NTSB finishes the investigation, it appears much more likely that it's pilot error, he pulled a wing off, versus an aircraft mechanical failure.
The aircraft I flew until recently had Flint tip tanks. They are required to have (approximately) 12 gallons unitl the aircraft's gross weight was reduced (I don't remember the numbers). My technique was to fill the tips, put in the fuel required for the leg in the mains. I would burn the mains until they were about to go below 20 gallons per side, then transfer the tips to land with about 20 gallons per side, well in excess of the 45 minutes required.