The School of Hard Knocks - S1-E9
Revealing mistake: In the English dub, when showing the front of the flyer, it has filler text that is not related to what it is about. Also, its Poké Balls are slightly transparent and its picture can be seen through it. (00:05:43)
The School of Hard Knocks - S1-E9
Continuity mistake: After the title card, Ash and Misty have their bags on, but as the shot progresses, they will occasionally disappear. (00:02:03 - 00:02:58)
The School of Hard Knocks - S1-E9
Continuity mistake: When the doors to the training room open, there is no light aligned to the centre of the doors, but in the next shot, there is. (00:09:55)
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.