Many of the long shots were looped in the crowd scene following the accident, and other shots were dubbed with the audio track from other shots with which they were intercut. The audio and the mouth movements of the actors drift in and out of sync across the various shots in this scene.
When Mary falls into her trance the night she is playing organ alone in church, we see that she is playing the organ's pedals with her bare feet. But when the minister interrupts her playing and fires her, and she gets up from the organ to leave the church, she is wearing black loafers. Then when she steps outside the front steps to meet the waiting neighbor guy, she is wearing white heels.
In the department store where Mary discovers she is "invisible" she goes down an aisle with both hands out to her sides and clearly has no purse. The scene cuts to her leaving the store where she now has her purse.
In the racing scene the driver of the white car is quite active at the steering wheel while the car keeps going straight forward. At the end of the scene, she pulls the steering wheel to the left while the car moves extremely to the right side.
The service station garage, supposedly in Utah, has a poster on its wall advertising a sports show on TV station WIBW in Topeka, Kansas. (While it's generally true that broadcast stations west of the Mississippi River have call letters beginning with "K" instead of "W," WIBW is an actual station which still carries the same call letters today.)