Continuity mistake: Rex's kama is missing in a long shot of him and Ahsoka during the hangar bay firefight.
Continuity mistake: When Ahsoka runs out of the medical bay, Rex's kama is missing. (00:01:18)
Continuity mistake: Throughout the episode, clone troopers are wearing armor with four different types of markings; some have none, some bear the markings of the Coruscant Guard, some bear the markings of the 332d Company (Ahsoka's unit), and some bear the markings of the 501st Legion. However, at the end of the episode, the memorial in which clone trooper helmets are placed on their graves, only helmets with no markings and helmets with 332nd markings can be seen, none from the 501st Legion or Coruscant Guard.
Answer: I guess that 1) the King assumed that Ventress' droids were meant to capture the Jedi, not kill him outright. When she yells at OOM-224 to shoot Yoda, she evidently failed that expectation. 2) Sending out a bunch of Droidekas after it is plain that Master Yoda has clearly won is not a sign of good sportsmanship, either.