When April picks up Frank in her car outside his house, both the driver-side and passenger-side windows are up. But every time the camera is behind either of their heads while they're talking in the car, their hair can be seen blowing from the wind coming through the open car window where the camera is mounted.
The passenger-side shoulder belt in April's car is present for Bernice but missing for Frank.
The ultrasound picture at six weeks is not developmentally correct. At six weeks, the baby's features (hands, spine, etc.) would not be able to be distinguished; it would look more like a bean in shape.
(at around 1h 20 mins) When Bernice confronts April at Frank's place, a member of the crew can be seen for a few seconds in the lower left hand corner of the screen.
Barbetta is on 46th between 8th and 9th. Traffic goes west to east. But when they come out of the restaurant and walk to the car (which would be going east) the cars are all parked going west, and April backs her car up from west to east. There are also no clothing boutiques along that stretch of the street. And the cosmetic counter where Bernice says she worked would not be towards the Hudson where she points.
Frank tells April that she could not have been conceived by Steve McQueen, as he spent May to October 1966 filming The Sand Pebbles (1966) along the Yangtze. However, Americans effectively were barred from mainland China at the time; McQueen's movie was filmed in Taiwan and Hong Kong.
Bernice tells April she was conceived at a drive-in showing Bullitt (1968). But the film reveals April was born during April, 1967. Bullitt was made in 1968.