The General - S4-E8
Continuity mistake: When the 501st are pushing towards the Umbaran Airbase, most of the injured clones Kix drags away are missing their 501st markings, then in the next shot, they have the markings. (00:01:28)
The General - S4-E8
Continuity mistake: Pong Krell's goatee is missing at the end, when he accepts Rex's report that the base has been successfully captured. (00:21:02)
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.