Continuity mistake: After King Louis stabs d'Artagnan with the dagger, the good brother (Phillipe), rushes him and Louis drops the dagger to the prison floor. However, in the next scene, a close-up of the two brothers fighting, Louis has the dagger in his hand again.
Factual error: Six years in a mask and Philippe's teeth are in perfect condition. All that time without brushing or flossing, you'd think he'd have lost some teeth or been in wracking pain from toothaches.
Answer: Both Louis and Philippe are actually D'Artagnan's children. This is why D'Artagnan continues to defend Louis for much of the early part of the film, despite the King's callousness, because he feels that he must defend his son, even against his oldest friends. It's only when he discovers Philippe and realises that he has another son, a humble and decent man, that he's finally able to feel pride as a father and can stand against Louis and his excesses.
Tailkinker ★