I agree that Justin noticed it too,despote the fact he lost his ability to "read" Brian at that point.
I was just rewatching 205 and I find it quite symbolic that when Justin sees that computure Brian brought him he says it's called false hope. Brian never gave Justin false hope, he always loved him and belived in him. he just didn't know how to put that into words. it was Ethan who gave Justin false hopes.IMO, and Justin belived them for a while.