When Mannix is firing at a shooting range, he fires the last shot in a magazine, and the action obviously remains open. Yet in the next frame, without reloading, Mannix fires another round.
A flyer on a wall in the pool hall advertises boxing matches on Saturday, March 22nd, which was on a Wednesday in 1967. The next Saturday, March 22nd wouldn't be until 1969. The most recent previous Saturday, March 22nd was in 1958. The flyer doesn't seem to be nine years old so apparently the flyer is advertising boxing matches about 18 months into the future, which wouldn't happen.