Savage Land, Strange Heart (1) - S3-E8
Plot hole: When Kazar discovers that Sauron is really his friend Karl Lykos, Lykos reveals that he was turned into Sauron by Mr. Sinister. However, in the season 2 episode Mojovision when Sauron was attacking Shana, Magneto already knew who Sauron was. Magneto was the master of the Savage Land mutates years before Mr. Sinister was and hadn't been to the Savage Land for many years before then, so if Magneto already knew who Sauron was, then it couldn't have been Mr. Sinister who created him. (00:19:46)
Savage Land, Strange Heart (2) - S3-E9
Continuity mistake: When the fully regenerated Garokk emerges from the mountain, his loincloth is an orange-brown color. A couple of shots later, it is now grayish-brown. (00:17:14)
Savage Land, Strange Heart (1) - S3-E8
Audio problem: When Kazar is saying "That should hold him for a while" after trapping the T-rex in the pit, his mouth isn't moving. (00:14:46)
Savage Land, Strange Heart (1) - S3-E8
Continuity mistake: When Lykos departed the Savage Land in Magneto's aircraft, it only had one seat. Later in the episode after Sauron has abducted Storm, the aircraft now has two seats. (00:04:05 - 00:10:07)
Savage Land, Strange Heart (1) - S3-E8
Continuity mistake: When the X-Men are flying into the Savage Land, Beast is reading a book with a blank spine. After Wolverine tells Jubilee about Garokk, Beast's book suddenly has writing on the spine. (00:13:08)
Savage Land, Strange Heart (1) - S3-E8
Continuity mistake: When Lykos transforming into Kazar, his wings tear out of his jacket sleeves, and are incorrectly colored the same brown as the jacket. A couple of shots later, his wings have disappeared and don't form again until his entire jacket is torn off. (00:07:13)
Savage Land, Strange Heart (2) - S3-E9
Revealing mistake: When Storm is saying "Rain, lightning, thunder," the flashing green effect on her eyes sometimes appears on her cheeks instead. (00:02:21)
Savage Land, Strange Heart (2) - S3-E9
Other mistake: When Storm is directing a surge of lightning at the monolith of Garokk after telling Rogue to stay back, the plume of smoke coming from the volcano in the background is completely motionless. (00:16:49)
Savage Land, Strange Heart (2) - S3-E9
Continuity mistake: When the giant monolith of Garokk forms out of the mountain, the markings around its eyes are red. In subsequent shots, the markings are now the same gray color as the rest of the monolith. (00:13:18)
Savage Land, Strange Heart (1) - S3-E8
Continuity mistake: When Beast catches Rogue after Sauron tosses her, her black headband briefly turns white. (00:17:52)
Answer: Chris Potter, the original Gambit voice actor, did indeed quit the role in the 4th season. His last episode was The Phalanx Covenant Part 1 so it seems reasonable that Fox would limit the use of the character even though it was recast. It doesn't appear that Potter left the role due to animosity, he stated in an interview that he wished to play Gambit in the first live action X-Men film.
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