Continuity mistake: Frasier picks up a couple of paper bags full of stuff for a picnic he is going on with Charlotte and her boyfriend - there is a fabric string/tie hanging out of one of the bags as he heads for the door but when he gets there, it has disappeared.
Audio problem: There are two audio problems in this episode, both in the same scene. Frasier is in his apt. talking to Niles, Daphne, and Martin. After Marty says, "Wow, really?", we hear a couple of garbled words while Niles' lips move. Then as Frasier heads to the door, Daphne asks, "How'd he hurt himself anyway?" While she is saying this, we can hear a phone ringing faintly. It is not coming from on stage, no one moves to answer a phone, and it has no part of the plot.