Since fossil fuel theory is an absolute and unassailable truth for the eternity, this the only conclusion that will and could be reached: Titan dinosaurs did it.
Biogenic formation is the most accepted explanation for the vast majority of petroleum reseves on Earth, mainly because of the presence of biogenic markers. However, abiogenic formation is not only possible but is acknowledged as the origins of several deep-crust deposits of methane and other hyrdocarbon gases.
Considering that Titan's conditions closely match those that are thought to be conducive to the abiogenetic formation of hydrocarbons, and that hyrdogen and carbon are known to be quite ubiquitous throughout the solar system, it is no scientific shock to find lots of petroleum on Titan.
Oh, and the closest thing to an 'absolute and unassailable truth' about 'fossil fuel theory' is that it didn't come from dinosaurs. If you really think that is what scientists say then you obviously don't read anything they write.
Actually fossil fuels coming from Dinosaurs is a misconception, they more than likely came from algae and bacteria not the drippins from dead dinosaurs.