I agree. I think that Revan was impatient, so he sought the quick and easy path. This of course, as we know from Yoda, leads to the dark side. I don't think that he fell until he and Malak discovered the Star Forge. The darkness that emanated from it must have corrupted them, thus turning them into Sith. But that's just my crazy theory
Anyway, whoo hoo, 200th post! (w00t) Do I get a prize?