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)
Continuity mistake: When Fives is telling Rex he, Jesse and Hardcase are going through with their plan, Jesse and Hardcase switch places. (00:12:26)
Continuity mistake: When Krell is getting in Fives' face about who is going to take the blame for Fives and Jesse disobeying orders, the markings on Jesse's armour are missing. (00:21:21)
Continuity mistake: When Rex releases Fives and Jesse from the brig, Fives' kama is missing as he stands up. (00:11:00)
Continuity mistake: When Krell jumps out of the tower window, his blue lightsaber is in his right hand, but when he lands, his sabers have swapped hands, with the green one in his right instead. (00:12:21)
Continuity mistake: Tup attracts Krell's attention by firing two shots at him, but Krell is then seen deflecting three blaster bolts. (00:15:41)
Continuity mistake: When Rex begins to question Krell in the brig, Fives' kama is missing. (00:16:55)
Continuity mistake: When Anakin and Ahsoka are pinned down behind cover by the sniper droids, the damage the droids' blaster shots on the walls the Jedi are hiding behind changes whenever it's shown. (00:14:26)
Slaves of the Republic - S4-E12
Continuity mistake: When Ahsoka threatens Queen Miraj, she's holding her primary lightsaber. When she's shocked unconscious and falls to the ground, it's her smaller shoto that rolls onto the floor. (00:14:44)
Continuity mistake: At the beginning of the queen's audience with Count Dooku, when he says, "But I was invited - by your faithful advisor. He's concerned over how attached you've become to Skywalker," there is a shot of Dooku walking up the room, then it cuts away to the queen and Atai Molec (the advisor in question), and when it cuts back to Dooku, he walks through the same part of the throne room as in the previous shot of him. Take note of a screen on the side of the room - it's in the same position both shots. (00:05:35)
Continuity mistake: When Queen Miraj gets angry with Atai and Count Dooku, she throws her glass to the floor and the sound of shattering is heard. But after Anakin arrives, the glass is lying on the floor unbroken. (00:09:10)
Continuity mistake: When Anakin is cutting through the door of the Kadavo facility after Master Plo's forces have arrived, the position of the hole he's making is different from when it was previously shown. When he finishes cutting the hole and kicks in the cut-out section of door, the hole is back in its original position. (00:14:25)
Continuity mistake: After Rako Hardeen orders a drink at a cantina, when the bartender pulls a bottle out from under the bar, it's corked when he takes it out and raises it to pour, but the cork is suddenly missing when he's pouring, although he didn't stop to take the cork out. (00:04:00)
Continuity mistake: When Cad Bane is taken into custody by a clone trooper, the trooper changes from a shock trooper to a standard trooper between shots. (00:14:40)
Continuity mistake: When Dooku Force-throws some cutlery and dishes at Anakin, he gets a fork and a knife stuck in his prosthetic arm, but when he pulls them out, there is no damage to the protective glove he wears over it.
Continuity mistake: When the two factions of Hondo's pirates are fighting each other, the ones who sided with Maul and Savage are using blasters that fire red bolts, while the ones that stuck with Hondo shoot blue bolts. When Hondo persuades the traitors to work for him again and they attack the two Sith, all of the pirates' blasters are now firing blue bolts. This is Star Wars, not G.I. Joe, and weapons don't just change colour like that.
Continuity mistake: While Anakin and Obi-Wan are talking about Rush Clovis, a droid head Anakin is working on disappears from a table between shots. (00:07:30)
Continuity mistake: When Yoda arrives at Korriban, the wings of his starfighter open up when he flies down to the planet. However, in the second shot of him flying down, the wings are closed. (00:01:10)
Continuity mistake: When Jesse and Crosshair are glaring at each other onboard the gunship, Kix has his right arm raised to grab hold of one of the handholds. When Jesse starts forward after Crosshair calls him a "reg", Kix's arm is suddenly down, but when Cody tells everyone to cut the chatter, Kix's arm is raised again. (00:07:00)
Answer: Dooku never accepted Ventress as his apprentice, as far as I know; he just kept her as his devoted personal assassin. In Phantom Menace, it is stated that there can be only two Sith at a time, to prevent a power struggle in the lower ranks. To accept Ventress as an apprentice, Dooku would have violated that rule.