Naruto Shippuuden Episode 83

[ASSpirine]

Then Chouji stood at a perfect place and reacted very well.

[Buffalobiian]

Then Chouji stood at a perfect place and reacted very well.

That's true, but do remember that Hidan/Shikamaru forced Kakuzu into that position for Chouji. To me, Shikamaru's still genuinely surprised Kakuzu dodged the swing, that much was evident. Being the brain that he is though, it didn't take him much effort to adapt his current situation with that of another plan.