Revealing mistake: When the battle droid commander orders the tanks to stop because they can't go any further into the forest, the fingers of the droid nearest to the camera clip through the wall of its tank. (00:07:49)
Revealing mistake: During the exchange between Hevy and Cutup regarding Echo's enjoyment of their dull posting, the left pauldron of Hevy's armour is positioned weirdly, clipping through his arm at the bottom. (00:01:34)
Bombad Jedi - S1-E8
Revealing mistake: When Jar Jar demands that Padmé be released while posing as a Jedi, his ears clip through the back of the hood he's wearing. (00:19:16)
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.