I would think an accidental direct hit by a plane on fuel tanks would be unlikely. If the pilot knew they were going down, and not likely to survive anyway, I would EXPECT him to try to guide the plane AWAY from something as potentially catastrophic as that. Also, I'd expect to hear of reports of him communicating with the tower. A mayday of something.
(see, I'm still here)
I agree. I think the chances of a plane hitting those tanks accidently is infinitesimally small.
The story has to give you pause no matter what the ultimate cause.