When Bellick goes to see Westmoreland to find out who killed C.O Bob, he lit a cigarette then placed the packet back in his pocket as he enters Westmoreland's cell, but when he sits down in the cell you see him put the packet in his pocket again.
When Nick Savrinn is taking the boxes out of the car he asks Veronica to help him out because there are five boxes. When Lucas is using the dolly to bring the boxes inside, there are only four boxes and neither Nick or Veronica is carrying one.
Firearm suppressors do not make gunshots silent as depicted. They only reduce the report of the gunshot enough to prevent hearing damage. The abbreviated suppressor wielded by Kellerman would have certainly been loud enough to draw the attention of anybody nearby.
Michael states in the beginning that "they strap my brother to an electric chair, send 50,000 volts coursing through his body". Electric chairs use about 2,500 volts of electricity.
Michael is discussing the road that connects New York and California as "Route 66." The actual road that connects New York to California is "U.S. Route 50." Route 66 connects Illinois and California.