Continuity mistake: Just after Sydney gets the book snatched from her by the guy in car, her hands stay near her body and don't move, but in the next shot her hands are thrown out to the side to add a surprised effect.
Continuity mistake: When Nigel is being held at gunpoint, the distance of the gun from Nigel's neck changes between shots when they are in the shipwreck.
Factual error: The scenery is set in Berlin, following the 1989 Re-Union of Germany. Only thing is: the guards at the archive building use AK-47s, while after the Re-Union, the East German National People's Army and the West German Bundeswehr (Federal Defense Force) were joined - and the West Germans don't use any AKs.
Continuity mistake: When Sydney has the "Book of Love" from the limo she starts to read it. In one shot she holds the book firmly with her hands wrapped around it. But when the motorcyclist grabs it she is holding the bottom of the book in the tip of her fingers [To aid the stunt].
Other mistake: The entire Buddha structure had tip over onto its side yet the bowl and its pedestal inside the structure remained the right way up ready for Sydney and Nigel to come and find it.
Factual error: Entering the secret room in the old part of the castle, the protagonists find there the ring and a specific painting...but doing so, they casually walk in front of another painting kinda hidden in the background...a perfect copy of the uber-famous Leonardo Da Vinci painting "Lady with an Ermine"! Considering that the painting was finished in 1490, the opening caption of the episode said "1430." Even if after the incident the young lord lived into his 80s or 90s, there surely wouldn't be a perfect copy of it in his secret hideout. (00:25:40)
Revealing mistake: When Nigel shows Lord Aubrey's page from the genealogy book of the various lords of the house, the text does not deal with the lord at all, but it's Latin filler from Celsus' "De Medicina." (00:22:10)
Continuity mistake: Curled up in the bunk bed, Nigel apologizes for the plot contrivance hit to Sydney's noggin. He is clutching the book, with his hands in obviously different spots between the two shots. (00:10:55)
Continuity mistake: Sydney is reminiscing about her Peruvian fling; in the foreground her client is taking a sip of wine, and the glass is about half empty. It is already much fuller in the next shot. (00:09:20)
Other mistake: In the Romeo & Juliet-like beginning of the story, Calum looks at his own hand and discovers Elena's blood. Obviously censorship ratings prevent the scene from being realistic and he has barely a smudge of blood on his own hand, but Elena was lying dead on top of him; the fact that his clothes are absolutely pristine for the rest of the scene is laughable - at least she could have gutted herself a little bit on the side and not where she would inevitably bleed him a river right on his white shirt. (00:02:55)
Other mistake: Calum fights off Elena's father and is chased away by the guards. Somehow he has a fight on the top of the stairs with 2 guards, but it takes in excess of 40 seconds for the previous pursuers to catch up with him. (00:04:25)
Smoking Gun - S1-E2
Character mistake: When the bad guys put the generator in front of the air vent, Nigel looks at the white smoke and pointing at it says "Carbon monoxide." Carbon monoxide is colorless, white smoke is mostly condensed vapor. (00:35:20)
Smoking Gun - S1-E2
Plot hole: Lori managed to get to the bunker through the elevator because the modern board was still replaced by the antique one. But that implies that she was able to call the elevator as normal. And if people can just call the elevator back but the normal control board has been replaced, then they wouldn't be able to use the elevator as normal, creating quite a problem in a huge hotel. Sydney earlier was not able to switch the board back to the normal one since she went out from a (mysterious?) exit/entrance, so this situation makes no sense.
Smoking Gun - S1-E2
Other mistake: Somehow, the pineapple grenade that explodes right against the room's baseboard punches a hole in a thick stone wall, but in the middle of it, preserving the base and creating a gap in a diamond shape that radiates from mid-height. (00:17:40)
Smoking Gun - S1-E2
Other mistake: The episode begins with a caption; "Chicago, 1930." In present day, through internet magic (hotel records from early 1900s somehow digitalized and publicly available!) Nigel and Sydney talk about the history (fictional, no actual historical basis) of the Roxbury. Nigel says that the original owner went out of business "after the war", then the company was sold, and the hotel refurbished, despite being, Sydney says, "only 5 years old." Later in the episode, Sydney looks at a plaque from the Chicago Historical Board that dates the elevator as "circa 1901." (00:12:35)
Continuity mistake: When Sydney talks her inexperienced assistance into a reckless climb, Nigel is leaning against he truck in the close-up, when he was not in the rest of the chat. (00:30:25)
Continuity mistake: Sydney and Nigel are talking with Robert Blaine at the beginning of the episode. When he mentions the Nepalese people there's a close-up on them. One student wearing a white T-shirt is walking up some steps - but in the next shot he is walking down other steps situated earlier in his path. A few seconds later, another flub with an extra; Nigel stops the museum curator just as an extra wearing white clothes enters the frame, but the person is gone in the sudden cut. (00:06:25)
Smoking Gun - S1-E2
Continuity mistake: In the prologue, Young Murray finds a man he does not know sitting at a table. He advances towards him in a wide shot of the room, and the man positions his left hand on the corner of the table, but in the following closer angle on him, his hands are close together exactly like in the initial shot by the same angle. It's like the middle one never happened. (00:03:10)
Visible crew/equipment: When Sydney taps the shoulder of the baddie who nearly disarmed Nigel, a strong light is cast on his face just before the cut. Nobody was supposed to point a flashlight or a torch at the fight. (00:38:15)
Continuity mistake: When Sydney Fox retrieves the parchment with the map, she holds it differently (probably turned 180°) between the close-up and the reverse shots. It also should be noted that the world-class archaeologist just casually dumps on the floor like a piece of garbage a ornate XVI century flask. (00:23:50)