Don and Rebecca are sitting at a table when Don asked Rebecca to marry him she declines and an argument follows. Don leaves and Rebecca is sitting at the table crying. A moment later Frasier yells out the door to Don who is long gone but in the very next scene as Norm and Cliff are watching TV Don can be scene sitting back at the table and Rebecca is nowhere to be found.
When Sam and Diane are on the aircraft preparing to fly to Los Angeles, the establishing shot shows a Lockheed L-1011, a widebody aircraft. The following shots, showing the interior of the aircraft, clearly show a narrowbody aircraft.
In Melville's, when Sam says the line "and you just brought along your one-man Warren Commission there" the line is clearly overdubbed as the words don't match his mouth movements.
Five minutes in, the scene shifts to Norm and the bar crowd watching the Cable Ace Awards. The boom mic is visible in the upper left hand corner of the frame.