Lee Sedol definitely did not look like he was in top form there. I would say (as an amateur) his play in Game 2 was far better. It was the funky clamp position that perhaps forced AlphaGo to start falling apart this game. [0]

I wonder if Lee Sedol can find a way to replicate that in Game 5.

[0]: https://twitter.com/demishassabis/status/708928006400581632