I do think Mace Windu is the bad egg - I can't see it being By-Gone - sorry, Qui-Gon as his voice can be heard shouting 'Anakin, no!' after the Tusken massacre and Jocasta Nu is just TOO obvious...besides, after Jango is beheaded there seems to be some communication between Mace and Dooku and this ties in with the look on Obi-Wan's face in Star Wars when he sees R2 and tells Luke Darth Vader killed Anakin . Unlike Mace Windu Obi-Wan isn't a good liar methinks...