Claire and Lizzie throw Dustin and the babysitter out of the apartment. When they are in the elevator, Dustin's painted eyebrows become real eyebrows.
While Alexis is getting ready for her first date with Tank, she had a margarita in her left hand. Her roommate walks toward her with a leopard-print blouse. Mid-sentence, the camera angle changes, Alexis is wearing the leopard-print blouse and black scarf, and the margarita is in her right hand.
When Alexis and Tank are kissing inside the church, lipstick is smeared all over Tank's face. When he goes to the bathroom and looks in the mirror, the lipstick has disappeared.
At the beginning, when Alexis is makes her smoothie, Rachel takes a sip of the green drink before Alexis pours it.
When Dustin and Tank leave Alexis' apartment, the door is closed, but no one is nearby to close it.
Tank and others smoke in restaurants and bars. The movie is set in Boston. In 2004, Massachusetts banned smoking in all indoor public places, including restaurants and bars.
When the first of Dustin's eyebrows is shaved off, it is clear that he has prosthetic makeup over the area, as the ridge of that eyebrow is suddenly quite a bit lower than the ridge with the remaining brow.
In a bar scene, hearing aid or ear plug is visible in Alec Baldwin's ear but is not there in close-ups.