Plot hole: Paige sees Margo leading the labor rally at the citrus factory, and then is stopped by a security guard. In the next scene, Margo and her sisters are entering the manor, and then after that Paige is thrown out of the factory. But how did Margo get from the factory to the manor before Paige was thrown out, when she was in the middle of the rally?
Continuity mistake: During the scene when Paige goes to the citrus plant during the labor rally, her pink blouse is quite short, baring her entire midriff. When the security guard throws Paige out of the plant, Rose McGowan's stunt double is wearing a shirt in the same pink color, but it reaches all the way down to her waistline.
Continuity mistake: The Stillman sisters strip the Charmed Ones' powers by using the same spell as Aunt Gail did in Season 2 (How to Make a Quilt Out of Americans). But in that episode the Charmed Ones had to first drink a potion and Aunt Gail needed to wait a certain amount of time (at least 30 minutes) before the spell worked. In the Power of Three Blondes, the Charmed Ones never drank a potion and lost their powers before the Stillman sisters even finished the spell.
Plot hole: When Paige tries to orb to prove her identity to Chris, she can't because Margo has cast an anti-orbing spell. But that's not possible. The Charmed Ones and Chris all orbed into the room, and Margo couldn't have cast a spell after that, or we would have seen it happen.