Oh I can see it, the more I think about it the more I agree with the theory.... Dexter has had his Father in his head since the first season so it only makes sense that Travis could have the same thing (particularly when they reinforced the idea by letting Dexter's brother have a ride along to Omaha).

This is an interesting season of Dexter, there is a lot going (without it being over the top and annoying like the second and third seasons were, to me).