That could mean there probably was no 'accident', it was probably an 'incident'. We've had several of each around here, and in all cases FAA/NTSB checks fuel quantity (f they get involved). They want to know - starvation or exhaustion? It's going to be hard to find a pattern if no one measures fuel remaining after one of these episodes. Was there fuel left? If yes, how much and why didn't it work? If not, where did it go? In this case, the pilot says he had plenty of fuel for his flight (plus reserves), but the engine disagreed. Measuring the remaining fuel in the tank seems like a good way to start, if you really do want to figure out what happened. But the pilot says watever fuel was left splashed out through the vent so an empty tank won't mean anything.