I like the lawrence of arabia link, he rebels against his superiors to carry out his own agenda, which is what david may do in the film. Maybe david has just snapped after the abuse from humans and the engineer, thats a bit shallow for a story this great.
other thoughts........
David is really a espionage/sabotage/destroy android, as we can see in prometheus, and plays possum but is actually undermining everyone for weylands agenda. David has the engineers knowledge, their weapons, experiment data from the crew, and their ships, that means weyland do too, isnt it better to eliminate the engineers anyway, especially as they were going to 'do' earth and 'did' david? Id be angry if i had my head ripped off.