Continuity mistake: When Ash says, "We gotta make sure we don't get separated," Misty's right arm is violet, but in the next shot, it is skin-colour. (00:01:32)
Continuity mistake: When Misty asks if Brock knows how scared it makes her feel when he yells, the purple strap on her bag turns yellow like her shirt. (00:02:04)
Continuity mistake: When Brock says if there are Ghost-type Pokémon, then they can show themselves to them, he, Ash, and Misty are between a doorway, but in the next shot, they are not. (00:08:33)
Continuity mistake: When Ash asks how they would succeed in their match at the Saffron City Gym if they do not go back into the Pokémon Tower, Charmander is on a connecting part of the path, but in the next shot, he is not. Also, Pikachu is on one completely, but in the next shot, he is not. (00:10:31)
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.