Yeah, just to echo to what everyone else is saying--Context. Matters.
Also, with B5 you should always remember what G'Kar said to Sakai way back in 'Mind War': "No one here is exactly what he appears. Not Mollari, not Delenn, not Sinclair .. and not me." True to form, by this point in the show we know who and what Sinclair & Delenn turned out to be and now we get to begin to find out who Londo and G'Kar really are.
Well, we're not really beginning to find out who Londo is anymore, and thats my problem. I wanted to learn what would happen to Londo over the course of the rest of the show. Now, I know, and it makes every appearance of his from now on pointless. There is no mystery about what he'll do. He'll side with the shadows until the very end. The only question is how G'Kar got into his palace to kill him, but at this point I'll just assume he was Londo's slave. Either that, or he gained the ability to teleport. Why not? It fits the stupidity of these sections.