Corrected entry: In this episode Frasier and Niles talk about how they met Marie when they were children because Martin was friends with her father, Duke, therefore, Frasier and Niles would have known Duke as well. But in the episode "Duke's, We Hardly Knew Ye", they met Duke for the first time.littlestar
Corrected entry: Frasier is getting everyone together to have a shot at the pinata and we can see a little girl in a bright pink dress running on the other side of the picnic table. As Frasier says "one for the children", she is suddenly standing right in front of him. There was no time for her to get there naturally.
Corrected entry: Early on in the show, Martin, Niles and Frasier are in the living room talking about Daphne and Donny - Frasier is addressing a long envelope. He gets up from the table with it in his left hand and walks towards his desk. He gestures with his empty right hand as he walks. He gets to his desk and suddenly the envelope is in his right hand, with no time to have switched it.
Corrected entry: Marty is comforting Eddie who he says has been taunted by a blue jay. This particular bird is not found in Seattle - it is found in much of North America but not west of the Rockies. Marty, who had spent all his live in Seattle, would not make this mistake - and if he had spotted a blue jay there it would have been highly unusual and remarked on.