When Andrew and Portia are playing chess in the park, the chess board is at first very unusually set up as most of Portia's pieces are on the board side closer to Andrew and vice versa. In the next moment, the board has changed completely.
During the conversation between Andrew and 'Sir' after Andrew jumped out the window, a clump of grass caught in Andrew's neck joint appears and disappears.
When Andrew is walking through the park with Portia, his shirt is wide open. When they stop to talk, it is almost closed. When they walk again, it is open again.
'Sir' tells Andrew that he has stopped referring to himself as "One", however, during their first visit with Dennis Mansky at Northam Robotics, 'Sir' quotes Andrew as having said, "I enjoy doing this."
When Andrew first arrives in San Francisco and watches Galatea at the market the couple walking behind him shows up multiple times in the same position as the view switches back and forth.
At the North Am building, Sir asks Andrew to come to the window. Andrew refuses. This is a direct violation of the second law of robotics, which states that a robot must obey the order of a human being unless doing so conflicts with the first law. Andrew coming to the window would not have harmed a human being.
When Andrew goes to Lloyd to sue for information as to the whereabouts of his robot counterparts, Lloyd states "the Freedom of Information Act does not cover suits by robots.".
There is nothing in the act that states that it is exclusively for humans, although this could be an attempt by Lloyd to halt Andrew's request.
The delivery van that brings Andrew is supposed to be Electric, but it has a tailpipe which are not required for this type of vehicle. This is not a goof if the vehicle is a hydrogen or similarly powered vehicle which while running on electricity would have a water by-product which needs an exhaust pipe.
The final scene in which the nurse robot stops life support systems on request is invalid; the First Law of Robotics would have prevented it. No amount of begging would result in a positronic robot assisting in suicide or euthanasia. In fact, according to Asimov's stories, even witnessing a human being hurt might destroy a robot's positronic brain and the movie acknowledges the Three Laws of Robotics.