Deliberate mistake: During the 6/11/04 episode, Jax and Courtney are having dinner in Italy. Carly, who is in New York, does some sleuthing, finds out where Jax and Courtney are, and flies to Italy. Miraculously, Carly manges to fly from New York to Italy and arrive while Jax and Courtney are still eating dinner.
Deliberate mistake: During the 11/15/04 episode, Alcazar and Lois make love in his living room. At the end of the episode, someone knocks on the door. Rather than go in the bedroom, Lois remains in the living room while Alcazar answers the door. Of course, it's Lois' teenage daughter, Brooke, and she sees her mother naked in Alcazar's living room. Deliberate plot hole to faciliate a reason for Brooke to run away in the 11/16/04 epsiode.
Deliberate mistake: There is no way that Dylan and Brook Lynn are the same age according to the show's history. Dylan was conceived during Paul's and Tracy's marriage; in fact, on their honeymoon. Ned, Brook Lynn's father, didn't even know Brook Lynn's mother, Lois, at the time. She wasn't even a character, yet. Ned had to divorce his wife Jenny, meet Lois, date and become engaged, marry Lois and then they had Brook Lynn, which was about five years after Dylan was born.