Continuity mistake: When Holly and Paul are at the library viewing Paul's book, Holly encourages Paul to autograph the library's copy of his book. Paul grabs a pen off the library's counter and begins to write in the book, then in the next shot Paul once again takes the pen from the library counter to write in his book.
Continuity mistake: In the scene at the apartment, Holly is tossing lettuce in a bowl. Behind her is the stove top, where a pot is resting on an unlit hob, and a yellow bowl is to the right of this. In the next cut, we see a flame burning under what appears to be a different pot and the yellow bowl has moved closer to the said pot.