In the supermarket scene, the gunman grabs a bottle of Aunt Jemima to put the flames on his shoes out. When they cut back, it's a shelf of Mrs Butterworths.
The medallions are placed in individual pockets of the velvet purse and thus protected against touching yet, when the purse is handled, they make a distinct metal-to-metal clinking sound.
(at around 1h 19 mins) In the church confessional scene, the background audio has the priest reading from the Gospel according to Luke Chapter 23 Verse 24 ("Father forgive them for they know not what they do"). If this is St. Patrick's Cathedral, a Catholic church, this section of Luke would be read out loud only during Palm Sunday Mass (or at Mass during Holy Week) in observance of the Passion of Christ, (the verse is from the part of the Gospel describing the Crucifixion). With such an important reading going on, there would be no priests available to hear confession at that time, they'd all be celebrating the Mass.
When the medallions are put into the collection basket at the end of the movie they "clink". Gold does not resonate so, if they made a sound at all, it would be a dull "clunk".
(at around 1h 23 mins) Rollie launches hot dogs with a tennis ball lobber to attract the attention of the guard dogs. It seems unlikely this would work because guard dogs are trained to accept food only from their handlers.
(at around 3 mins) In the opening scene, the police arrive to confront the cyborg after he threw the bum through the window. One of the cops fires a warning shot and hits the cyborg in the head causing his blond wig to fall off and to bleed blue blood. When the cyborg raises his left hand to cover the head wound, it is obvious that it is somebody else's arm that is being used.
(at around 3 mins) The glass window breaks before the hobo crashes into it.
(at around 18 mins) When Rollie is telling Mike about his hidden camera, while he's talking he's reflected in a mirror and his mouth clearly isn't moving.
(at around 1h 10 mins) In the supermarket the hit man is smothered with clear plastic, completely covering his face and mouth, yet on the sound track you can hear him gasping, this is impossible.
When Silak is giving Rollie back his hidden camera, Silaks' response to Rollie saying its a transistor doesn't match.
When the characters are in the supermarket, the products on the shelves are all fully stocked and faced. Given that this is at closing time at the end of a busy day, there should be holes yet to be stocked.
Both Rollie and Leo should have been in prison for their involvement in the events of the first movie.
When Rollie calls Chris in N.J. he only dials seven numbers. He would have to dial long distance, which would entail dialing 11 digits.