Continuity mistake: When Piper and Leo confront the genie at the restaurant, the genie is eating food as fast as he can. At one point he gets a line of pasta sauce on his cheek. The shot changes, then goes right back to him only now the sauce is gone with no time for him to have wiped it off, especially since his hands are full of food.
Continuity mistake: In 'Morality Bites', Phoebe has her premonition about being executed while watching a news report on a baseball player, right after she and the others punish Pratt. When she returns in time at the end of the episode, they all watch the news report first and only afterwards look out the window and see Pratt.
Continuity mistake: In the teaser, Phoebe took off her messenger bag while she was sitting in the chair talking to Prue, and she left it there when she went up to get the door. For the rest of the scene at the house, including when Phoebe and Prue ran out of the door, Phoebe was not wearing the bag. Then, when we saw them outside immediately thereafter, Phoebe was wearing the bag again.
Continuity mistake: After Phoebe kisses Billy, she sees that the makeup over his lips has washed off and that they're in black and white again. While she applies more to him, the phone rings, Billy turns his head, and his lips are normal. In the next shot, they're back to being in black and white.
Continuity mistake: On 2/17/1999, Phoebe realizes that her past self, P. Russell, died on that same date in 1924, and was the same age as Phoebe is now. According to the family tree she is looking at, P. Russell was born on 7/2/1894, meaning that she was 29 upon her death. But Phoebe was born on 11/2/1975, according to that same family tree, making her only 23 at the time of this episode.
Continuity mistake: When Prue leaves Buckland's, she's wearing a red tank top, but when she arrives at Camp Skylark, her shirt is different, both in style and color. She can't have stopped to change, because it's mentioned she left the auction house and headed directly to the camp.