Stop trying to give prequel characters interesting motivations ;)

At least that would have been a role more worthy of Jackson. Windu as a secret disciple, sort of a Saruman character could have been very good.

There are no secret clues, I'm afraid. Watch the ~0:58 mark of this video of the ROTS duel with Dooku. While Obi Wan is engaged with Dooku, Anakin is directly behind Dooku and lowers his lightsaber and just stops fighting. The same poor choreography is at work in Palpatine's killing of the Jedi with Windu.

Fan Edits exist for implementing alternate visions, maybe yours is worth exploring by someone with the skill.