Yes, I heard that they might kill off Adi Gallia in TCW, even though she was already depicted dying on Boz Pity by Grievous. That got me wondering. How much continuity has Clone Wars screwed up so far?
Here are a few major ones I found, the Wikia links below have a few others listed.
"Since Episode IV, the Republic was known to have fought the Clone Wars, and the EU added several other conflicts, such as the Great Sith War; but in Episode II, it was stated that "there hasn't been a full-scale war since the formation of the Republic." The above-mentioned Ruusan Reformation also handled this discrepancy."
"Timothy Zahn, in his Thrawn trilogy, cast the Clone Masters as the opponent of the Galactic Republic in the Clone Wars, as several authors of the '90s considered that the cloners and their clones were the "villains." However, after Attack of the Clones revealed the clones were on the Republic's side, the Clone Masters were retconned into being renegades who did not attack until after the formation of the Empire."
"One example of a direct contradiction between The Clone Wars and Clone Wars is the use of Eta-2 Actis-class light interceptors at the same point in the timeline Anakin is knighted, whereas in The Clone Wars Delta-7B Aethersprite-class light interceptors are used, which were ostensibly used before the later Eta-2s. "
"For example, in the novelization, Anakin remarks that he has only read about Grievous' Magnaguards in an intel report, despite having fought them in the show."
"Another very noticeable continuity error is the fact that Anakin has his scar which he received shortly after the Battle of Rendili from Asajj Ventress. He then injured Ventress so severely she was forced to recuperate until the Battle of Boz Pity, after which she deserts the CIS and the war for good. However, as he was originally shown to receive his scar in 19 BBY, yet the series takes place in 21 BBY, this is a glaring continuity error."
Remember that the Clone Wars was not aired in chronological order. What is often considered in-show continuity error is usually just caused by episodes being aired in weird order. This includes the movie as well, it is chronologically not start of the CW storyline.
I also noticed many errors between the time of the Clone Wars and Episode III Revenge of the Sith. in TCW, which is set in the small three year period between Episodes II and III, Anakin battles General Grevious many times. However, in Episode III after Obi-Wan, Anakin, and the chancellor are caught in a ray shield and escorted to General Grevious, Grevious speaks to Anakin saying
I was expecting someone of your reputation to be, a bit older
He says this as if he has never met Anakin before, but this creates a plot hole in the entire timeline.
I would like to highlight an important continuity retcon that has been overlooked: Technological advancement of both Republic and Separatist armies.
Firstly, let's consider the old 2002-2005 Clone Wars multimedia project. By comparing the 2D cartoon, Dark Horse's Republic comics, Del Rey novels, and video games etc., we see that for much of the 3-year war, both sides maintain usage of the droids, vehicles and starships seen in the Battle of Geonosis in AOTC (Republic: Acclamator-class assault ships, SPHA-Ts, Delta-7 Aethersprite Jedi starfighters, V-19s; Separatist: Lucrehulk-class battleships/core ships, Vulture starfighters, etc.)
Only after Anakin is Knighted (30 months after Geonosis) do both sides switch to the equipment seen in ROTS (Venator-class star destroyers, ARC-170s, Eta-2 Actis, Tri-fighters, Providence-class cruisers, Munificent-class frigates, buzz droids, crab droids, etc.), complete with the respective red or blue paint jobs. For instance, we first see the new vehicles in action in Clone Wars Chapter 22 and in the Obsession comic, largely superseding or complementing the earlier vehicles.
In terms of clone trooper armor, everyone is in Phase I (including ARC troopers). Phase II armor is only first seen 24 months after Geonosis, in Republic #68: Armor.
Now let's consider the new Clone Wars timeline introduced in the 3D cartoon (2008-2013), where Anakin is Knighted mere months following the start of the war. From Wookieepedia, we know that all episodes featuring Anakin, Obi-Wan and Ahsoka in their very first character models occur in the war's 1st year--- and we already have the respective paint jobs on both sides' vehicles, plus Venators, ARC-170s, Providences and Munificents, and several newly-developed vessels for the series (e.g. Arquitens light cruiser, Nu attack shuttle, Delta 7B starfighter). Not forgetting crab and tri-droids.
As for the clones, they wear Phase I armor except for the ARC troopers (who wear experimental Phase II armor as seen in S03E01 Clone Cadets)
Moving on to the war's 2nd year where the trio changes their character models (from S03E10 Heroes on Both Sides onwards), the Seps introduce their Tri-fighter (first seen in S03E10's Battle of Sullust). Later on in the year (Season 4), all clones switch to Phase II armor. During the Battle of Umbara (S04E07-10), we see the Republic's new Z-95 Headhunter in action, apparently replacing the now-absent V-19s.
Moving on to the 3rd and final year of the war (Season 5 onwards), the Seps' HMP droid gunship is introduced during the Battle of Onderon (S05E02-5). The buzz droid makes its debut in S05E13 onboard the hijacked Venator cruiser bound for Carida. And finally, the Eta-2 Actis Jedi Interceptor replaces the Delta-7B in S05E17 during the Defense of Cato Neimoidia.
Thus in the new Clone Wars timeline, we see that the introduction of new vehicles and armor is more staggered than the abrupt makeover seen in the old timeline.
Hope this has been interesting.
There are continuity problems within the series itself. One minute Padme's Rodian Senator friend is dead, the next season he is alive. One season Ziro the Hutt escapes, the next he is back in prison, the next he is escaped and dead. The series is woefully bad at keeping continuity and it seems the writers didn't bother thinking outside of the first season. With Disney doing the 'Star Trek' rewrite to the universe, it may not matter.