Keep in mind that the second video is only a portion of Revan's story.
Comparing what's going on in that video to what reviews I have read about the novel (yeah I still haven't read the darn thing yet) I would have to say that it seems like Revan is becoming lost in his mind. He appears to no longer determine right from wrong, he is corrupted from his own eagerness to destroy the dark side by what ever means.
@2nd Video: This was through the perspective of the Imperial characters. This whole scene probably would never happen when playing as Republic.
I also think it is odd that it seemed like the Imperial characters were trying to save Revan.