About 5.04 and 5.10 I think it's going backward. Because present!Dean saw in 5.04 that future!Dean tried to kill Lucifer with the Colt, present!Dean then tried to find the Colt to kill Lucy in 5.10. But then either present or future!Dean knew yet that the gun couldn't kill Lucy. I think that's what you call paradox in time when you make time travel. You might change the future by seeing what the future is like when you happen to travel to the future. Confusing much? I am confused. :D