Possibly, but a large portion of the fuel is going to be driven into the ground, as well.
Here's my thinking:
IMagine the impact as the point of origin of an explosion (which it essentially is, at those speeds). You can model an explosion as an expanding sphere. Assuming equal distribution of shrapnel, debris, and fuel, with a point of origin at ground level, half the fuel gets buried into the ground and half sprays upwards or outwards, aerosolized by the force of impact, and igniting as soon as it spreads far enough to reach the right fuel-air mix. What's in the ground is not likely to aerosolize unless it's tossed back up somehow, and even then will likely stay atttached to dirt and other debris, so would not make an FAE-type explosion but just a burn. THis additional fuel may have burned, but I doubt it would aerosolize and explode.
Of course, in an impact like this, more debris would be thrown forward (inertia would carry more of it into the ground), so even 50% seems a bit wishful thiking to me. However, becasue of the complexity of the crash I can't rule anything out. Because it hit sideways and at an angle, the wings could have been torn in a manner to spread/spray more fuel, etc. However, I think a 50% baseline seems reasonable, and I don't think it'd get much higher than that, so I guesstimated 70%.
