In Michael Madsen's first scene talking to a Hitman, he has a Cigar and you see it change from long then to short in his mouth, and when he puts it back in the ashtray it is longer again.
After the apartment raid scene, Blacky pulls a house key (A type 68) out of the dead gunman's pocket. However, at the final showdown a different key is thrown down (A type 66).