When Frasier enters the apartment after Simon has moved in, Daphne sweeps Simon's things off the coffee table onto his duffel bag on the floor. In subsequent cuts showing the table, the pile is back, and eventually Daphne kneels down to start taking them from the table and putting them in the duffel bag as she talks with Frasier.
When Holly tells Frasier she's planning a Reggae festival on Mercer
Island, Frasier jokes that he'll remind himself "to take the Rasta-ferry
over and catch it." Mercer Island is accessed via the I-90 floating bridge, not a ferry.
The woman who brings the basket of clothes into Frasier's apartment says they were still wet when Daphne took them out of the dryer. Wet clothes would have fallen to the sidewalk in front of the building when Daphne tipped the basket over the balcony rail. To float into the traffic lanes, the clothes would have to be dry, and the weather would have to be windy.
We are initially told that Daphne has caused a "four-car accident". However, in the scene where the actual crashes are heard taking place, there are sounds from four crashes. Since the first crash involves two cars, a total of five cars must be involved in the accident, not four.
It's never explained why Daphne's brother has a Cockney accent from London even though he is from Manchester just like Daphne is. Thus, he should have the same Manc accent as Daphne has.