Caleidoscope - S2-E4
Character mistake: The chess set in Dr. Pierce's home office is set up incorrectly. When the men are set up properly, each player has a light colored square in the right-hand corner. The board as it appears in the show is set up so that the light-colored square is in each player's left-hand corner. This "beginner" mistake puts the king and queen in the wrong positions.
Second Time - S2-E13
Character mistake: When Kiera is begging one of the Freelancers to send her back she says she could "prevent Liber8 from ever coming to 2077." She should have either said "coming to 2012" or "leaving 2077."
Episode #5.3 - S5-E3
Character mistake: The chief baddie spells definitely as definately.