Pet Peeves: Burning Oil

During the D&D game at the Launch Night last night I was struck by one of my personal bugbears, particularly with people who then talk about any kind of "realism" in D&D.

Medieval lamp oil is not kerosene. Please think about this. When was oil discovered and refined? Are there oil derricks in your world? If not please don't have people going up in flames just because someone threw something that is nominally flammable at them. You can use olive oil in a lamp, if you douse me in olive oil and then try to torch me I am going to be angry but I'm unlikely to be wreathed in fire. The best oil you can hope for is whale oil if you want to be a realist.

So if you have burning oil traps in your game, please allow me to vault over obstructions, kick people over castle crenelations and generally have a high old time because it is no more unrealistic than your inability to grasp what was invented when.

And before anyone mention's Greek Fire, did the Byzantines put that rare, battlefield weapon in lamps and wander round their cellars with it?