After the dog comes out of Lori's bedroom with a shoe, Marilla goes into the bedroom. Mike is standing with the phone by the bed. He then moves to his left to in front of the window, where Marilla throws the shoe. There is a cutaway to the street, when the scene shifts back, the view is into an empty bedroom. Mike enters the frame from screen right with the phone and goes back to the bed. In the very next frame, he is back in front of the window when he says "Marilla".
In Marilla's apartment, the doors of the audio console are variously open and closed while Mike and Marilla are sitting on the couch.
When Maxie Stultz comes into the apartment and talks to Marilla, his tie is backwards. After the cut, as he walks towards the poker table, it is hanging straight.
A poster on the wall of the alley during the fight has a sticker (Opening Night) that varies from being across the name of the theatre (Crown Theatre) to dangling down.
Though the month-to-month wall calendar in Ned's office doesn't change even though at least six weeks have passed since he called Mike on the phone the day Mike met Marilla, this should not be considered a Goof; people often forget to change the calendar pages. This is especially understandable for someone who has recently fallen in love.
When Lori sings the ending of "Music Is Better Than Words", her voice is heard singing but her lips are not moving.
In Marilla's office, just after she's accepted the job with the Broadway show, the men's shoes make the sound of shoes on hard flooring, despite the fact that they're on a thick shag rug.
In his apartment when Mike answers the phone, the shadow of the boom mic is visible on his jacket.
While visiting Marineland, bottlenose dolphins are incorrectly referred to as porpoises, both by Mike and by the off-screen announcer of the dolphin show.