So Near, Yet So Farfetch'd - S1-E47
Continuity mistake: When Team Rocket takes off in the boat, it sinks. Their pokeballs float away, and Jessie says "Arbok and Lickitung are floating away!" But she doesn't catch Lickitung until Princess Versus Princess (Season 1, Episode 52).
KneverCharacter mistake: Brock states that the Diglett are plowing the ground and the Dugtrio are planting the trees, but the opposite is true (The Dugtrio are plowing, and the Diglett are planting).
Pokemon, I Choose You! - S1-E1
Continuity mistake: When the capsule containing the three pokeballs first opens up, you can see the names of the Pokemon etched into the balls (in Japanese). But when Ash picks them up, the names are gone.
KneverThe Ninja Poke-Showdown - S1-E32
Factual error: When Venonat uses Stun Spore, Ash tells Bulbasaur to use Whirlwind. Bulbasaur just blows the powder away with his mouth, but he doesn't use the Whirlwind attack. He can't learn Whirlwind in any of the games, and what Whirlwind is supposed to do is to blow the opposing Pokemon away. Ash could have just as easily told Bulbasaur to blow it away, but he instead chose to tell him to use a move that he can't possibly learn. The only Pokemon that can learn Whirlwind are either Flying types or Bug types; i.e., Pokemon with wings (with the exception of Makuhita and Hariyama, which weren't introduced until generation III, and did not exist at the time this episode aired). In The School of Hard Knocks (Season 1, Episode 9), a character mentions information regarding a Pokemon's levels, attacks, and information which is taken straight out of the game, so it's very clear that Bulbasaur should not be able to use Whirlwind.
KneverSuggested correction: Actually this is a result of mistranslation. In the original, Japanese version Ash orders Bulbasaur to "blow it away." He didn't say Whirlwind.
Character mistake: When Mandy brings out Golbat, Brock says "Kingler is really weak to air attacks." But Kingler's a Water type, which has no weakness to Flying type attacks.
KneverThe March of the Exeggutor Squad - S1-E41
Other mistake: The Pokemon Exeggcute is shown evolving in to an Exeggutor naturally. But the Pokemon Exeggcute can only evolve into an Exeggutor with the use of a leaf stone. In the Japanese version, there is a mention that something in these woods causes Exeggcute to evolve without using the Leaf Stone (when Exeggcute evolves, James even mentions that there is no stone). However, as this was skipped in the English version, it creates a plot hole.
Factual error: When we see that Dodrio's neck is tangled, the configuration doesn't make sense. It just looks like two bands of neck, but it doesn't reflect what it would actually look like if it was really tangled.
KneverCharacter mistake: During the recap, the narrator says that Ninetales had defeated Squirtle by using Ember, but Blaine ordered it to use Fire Spin.
KneverRevealing mistake: When Pikachu meets Puka on the cliff, we are treated to an aerial shot which shows the ocean below. There is sunlight reflecting off the surface, but as the camera moves, the lights pass in front of the two Pikachu on the cliff.
KneverBulbasaur and the Hidden Village - S1-E10
Other mistake: In the scene when Team Rocket tries to steal the Pokemon, Bulbasaur saves Oddish. Ash comes to help push Bulbasaur, and for a few frames you can see 2 sets of hand prints cut out where Ash's hands go.
ChevroletContinuity mistake: Jessie seems completely surprised when she's told that Voltorb can explode, but in The Ninja-Pokemon Showdown (Season 1, Episode 32), not only did she and the others find out what Voltorb are, they were all affected by the explosions as well.
KneverPokemon, I Choose You! - S1-E1
Audio problem: When Delia Ketchum says, "Oh, Ash, I'm so proud of you," the items that the Pallet Town townspeople are holding aren't being moved, however, the sound from banging of those items is heard. (00:07:35)
apikachu68Character mistake: When Team Rocket first sees Mandy doing his magic tricks, he produces a bunch of Pidgey. Meowth says "I like those Pidgeotto." He's dealt with Ash's Pidgeotto on numerous occasions, so there's no reason that he shouldn't be able to tell the difference.
Knever