In the morning of Erica's first stay in Henry's flat, we see Henry on the roof wearing the ring which Erica will give him days later as a present.
When Henry stands to leave the bus, he has a book in his left hand. When he steps to the pavement it is in his right hand. Next shot, he has no book.
When the mother/daughter team came near the principal's office and there was a flashback to when the student spat upon the principal's face. The principal wiped her face clean BUT there was no spit upon her face.
When Meredith is taking pictures early in the movie, she is using a Minolta camera. Subsequent scenes with her photographing, she's using a Canon.
After Henry leaves the bus and the girl follows him, the dress is on then off then on her right shoulder.
Boom mic visible reflected in the glass as Henry and Erica come out of the hospital.