Challenge of the Samurai - S1-E4
Continuity mistake: When Ash goes to get a Poké Ball for the first time, the ball is upside down, but in the next shot, it is upright. Also, behind the same Poké Ball, there is another one, but in the next shot, there is not. (00:03:19)
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.