Continuity mistake: When Ash, Misty, and Brock turn to Woodruff after he says for Ash to wait, Ash's right glove goes from covering his thumb to not covering it. (00:02:23)
Continuity mistake: When Ash turns after he wonders how the Heracross will help the Butterfree, the marks on his cheeks go from being present to being absent and then back to present. (00:03:02)
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.