Continuity mistake: In several shots throughout the episode, the black straps on Tracey's bag turn orange.
Continuity mistake: When Meowth says that he will use The Crystal Onix to make a charm, his white claws turn cream, like his body. (00:16:51)
Character mistake: Mateo orders his Charmeleon to use Ember against Crystal Onix but it uses Fire Spin instead. [It is yet another result of mistranslation. In the original version he orders Charmeleon to use Fire Spin.]. (00:18:42)
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.