For someone who cries "strawman!" so often, you sure make a lot of them yourself.
Show us where anyone has insisted "it must have been an electrical fault". All that has been pointed out is that electrical faults are a common, but not exclusive, cause of vehicle fires.
No one has suggested that an electrical fault is what melted the fuel tank, and that the fire started with fuel spilling from the tank. But because you know so little about automobiles, you don't realize that the greatest risk of fuel fire occurs in the engine compartment. If, in their panic to get out, the driver did leave the engine running, then that has a great potential to exacerbate the fire.
It's like you insist on not understanding anything that doesn't support the moronic conspiracy theory that you're totally not advocating here. It may allow you to continue to deny the simple truth, but it sure doesn't support the narrative of you being six steps ahead of anyone when you seemingly can't understand that a serious car fire can start well before the fuel tank is compromised.