But Anakin's slaying of Count Dooku happened at the beginning of Revenge of the Sith. Obi-Wan mentions that he first heard of 'Darth Sidious' from Count Dooku, which references the events of Attack of the Clones. When Obi-Wan and Ahsoka speak via hologram, we suddenly realize that The Clone Wars is now taking place after the first 30-minutes of Revenge of the Sith. Obi-Wan was mad at Anakin for killing Count Dooku
