Revealing mistake: When Ash's friends run over to him, as he dives into the pool, Pikachu can be running in midair. (00:14:27)
Revealing mistake: When Ash tells Lapras to go back to the ocean, his left arm is transparent. (00:14:18)
Revealing mistake: The pedal James presses when he slows down the lorry is the same one he used when speeding it up. This is due to the shot of him slowing the lorry down being a recycled shot of him speeding it up. (00:18:35)
Answer: He is a good guy but just found himself in a bad situation when he worked for Lysander. He didn't want him to harm Ash and his Pokémon when he was trying to get the special bond between Ash and his Greninja to work. He does leave Lysander and go back to being a good person.