Perhaps Revan never fell. The difference between a fall and a sacrifice is sometimes difficult, but I feel that Revan understood that difference, more than anyone knew. The galaxy would have fallen if Revan had not gone to war. Perhaps he became the dark lord out of necessity, to prevent a greater evil."
Kreia's character and much of what she said sucked and undermined the original game and much of what is great about the SW universe.
The stupid idea that Revan never "truly" fell to the dark side cheapens the original game and its important moment of revelation.