Evolution! That Mystery and Wonder!! - S8-E50
Other mistake: When Dr. Gordon says that the candy was created to improve a Pokémon's health, Caterpie mistakenly has seven segments instead of six. Also, Ash, Brock, and Pikachu go from being in front of a bookshelf to not being in front of one. Additionally, Max and Ash's bags go from being absent to being present. (00:08:17)
Evolution! That Mystery and Wonder!! - S8-E50
Other mistake: When Caterpie and the city are first seen, part of Caterpie's body is mistakenly coloured yellow instead of green. (00:09:26)
Evolution! That Mystery and Wonder!! - S8-E50
Other mistake: In the shot before the Pokémon Trainer's Choice, Caterpie's mouth is mistakenly coloured yellow instead of green. Also, its shadow appears in midair. (00:09:45)
Other mistake: When Juan says, "I won my five ribbons and entered the Grand Festival," his reflection in his tea is not reversed. (00:08:05)
Evolution! That Mystery and Wonder!! - S8-E50
Other mistake: When Ash and friends are first in the laboratory, Pikachu's right cheek pouch is missing. (00:03:13)
Evolution! That Mystery and Wonder!! - S8-E50
Other mistake: When Max asks if Zander studies with Dr. Gordon, Pikachu's right cheek pouch is missing. (00:03:50)
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.