Other mistake: When the camera pans across the Pikachu when they are surprised, one of them is missing its cheek pouches while another is missing its left one. (00:03:06)
Continuity mistake: When Brock says, "Yeah, I don't think too many people come this far into the forest, Ash," there is a tree with three branches directly emerging from its trunk, but in the next shot, it has two. (00:05:03)
Revealing mistake: When Ash goes to save the Pikachu in the river, he clips through his and Misty's bags. (00:05:25)
Continuity mistake: When Ash, Misty, and Brock are talking while they follow Pikachu, the button on Misty's shorts goes from blue to yellow constantly. (00:02:29)
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.