Very true. I've seen more than one instance where people died for their respective positions and the REAL answer turned out to be a "both/and" solution.
Regarding your experiences with your father, Gold's question about the reason behind those fossils being there really grabbed me. "How could you take a forest and mulch it all up so that it is a completely featureless big black substance and then find one leaf in it that is perfectly preserved?" His explanation is quite compelling.
One other element in the discussion -- one that I did not see among the others on the webpage I linked to -- is the depth at which modern drilling techniques are allowing us to access oil deposits. I've heard numbers as great as 8 miles. Well, barring a violent upheaval of the crust that would have devastated all life on Earth, it seems hugely unlikely -- I'll refraing from saying "impossible" -- that any part of the crust that was ever a heavily vegetated portion of the Earth's surface could have been subsumed to such a great depth. Even in such an instance, that it could have also carried with it and retained the majority of the biomass that had grown upon it, seems vanishingly unlikely.
So, I think that the "both/and" answer is most probably correct.