The cut on Bob's head goes from bandaged to gone and then reappears bandaged when he is talking with the defrocked priest.
When Bob first meets with Father Tom and they're talking while seated, at the end of the conversation, Father Tom is leaning either forwards or resting at the chair's back between shots.
The amount of sweat and blood on Bobby's shirt changes between shots in the women's bathroom at the hospital.
When Nadine puts the hat on the bed and lies down besides it, it's crushed in a regular camera angle, and not crushed when shown from above and it moves around between each shot.
When Bob is telling Rick and Nadine why they can't have a dog (around 27:00-30:00), Nadine is sitting on the arm of Rick's chair. Several times throughout the scene, her legs change position between shots without her having had time to do so.
When Heather Graham fakes a seizure as a diversion for a pharmacy robbery, a spinner rack of comics is seen. Almost none of the comics shown would have been available in a pharmacy in Portland in 1970, most being from either earlier or later years. Two of them are comics that would only have been available from comics shops -- and not until the year the movie was made.
HBO sign visible outside the hotel.
The bus passes a riding arena with blue polyethylene barrels for "barrel racing". In 1971 they would have been steel.
The Portland skyline has buildings visible that were not built until the 1980s.
In the last scene there is a 1975 or newer white and red colored Ford Van in the background. That boxy styled front end came to be in 1975 and ended in 1991.
In the opening shot with Bobby, the camera crew is reflected in the drugstore window.
When Bob finishes talking to his mom and she closes the back door, a crew member is reflected on the door's glass surface.