Kudos for calling the Sansa-Arya fake out on Littlefinger.
However, if we’re going to question the logic of every detail in the show, I would say that Littlefinger’s lack of awareness of his situation was probably the worst offense in the episode.
Cersei was Cersei, playing the game on multiple levels of dishonesty.
Jon was good old Ned, doing the stupidest thing possible in the name of honor.
Tyrion continued to be a fool, but not for the reason you mention. The key change in Tyrion is that when he found Daenerys, he lost his cynicism. Having a belief system and a goal of world peace do not produce the same pragmatism and results as a 100% committment to survival and squeezing as much pleasure as one can while on this mortal coil.
Sansa continued her slow evolution as a player, saying something to the effect “I’m a slow learner, but I still learned. Thank you for your lessons, Lord Baelish.”
Bran did his vision thing with a little more direction than usual, which I think shows that he still cares about his sisters (especially Arya). His “witnessing” of Littlefinger holding the knife to Ned Starks throat in season 1, and repeating the line that Ned should have never trusted Littlefinger was an amazing piece of jurisprudence. (Only in a primitive and superstitious place like Westeros do a green seer’s vision count as evidence in a court of law.) I think it proves my theory about how Bran’s vision is affected by strong emotions or thoughts in the people near him. As soon as Sansa accused him of being a traitor and a murderer, I think Littlefinger thought of Ned Stark, not Lady Arryn, because his life was consumed by Catelyn and Sansa.
Of every character in this episode, only Littlefinger failed to be consistent with his true self. He failed to do the very thing he told Sansa to do in episode 3: “Fight every battle, everywhere, always, in your mind. Everyone is your enemy, everyone is your friend. Every possible series of events is happening all at once. Live that way and nothing will surprise you. Everything that happens will be something you’ve seen before.”
Littlefinger knew that Sansa could be a witness against him for the death of Lady Arryn. He also knew that she didn’t love him, and that she blamed him for the Bolton marriage. So the most devious player in all of Westeros was slaughtered like a lamb because he had a crush on a girl half his age?
I don’t buy it.
While the scene was incredibly enjoyable, watching Littlefinger beg for his life and then get butchered without a real trial and execution left me feeling like fan service and a lack of time left in the show forced his character to be far less formidable that he should have been.
One other note: there was absolutely no doubt we would see the cruise ship scene after Jon was allowed in epidode 4 to explore at great depth in Daenerys’ cave.