Factual error: In "The Bloody Guardsman" case, the guardsmen are on sentry duty unarmed. Sentries always carry rifles.
Continuity mistake: The scene where Sherlock says "Vatican Cameos" he is seen to be facing the right side of the shot. Yet in the shot before that he is facing the left side of the shot from the back.
Continuity mistake: Sherlock is dancing with the bridesmaid towards the end. When they stop and are talking with Watson, Sherlock's hands keep switching from being behind him to in front of him, depending on the camera angle.
His Last Vow - S3-E4
Plot hole: Sherlock manages to convince Janine to let him into Magnussen's quarters after deceiving her into thinking he is going to propose. Several days later, she is enjoying her "revenge with profits" on Sherlock for his duplicity. Problem: There is no way she could have found out. She was out cold moments after letting Sherlock in, and Sherlock himself was shot by an assailant, which he had misidentified. Only Watson knew Sherlock's true intention, but we know he did not reveal it. The shooter and Magnussen did not know and had no opportunity to tell Janine anyway. (Plus, Magnussen's credibility is too low.) In fact, if I were the director, I wouldn't bother making up a motive for being a "grasping, opportunistic, publicity-hungry, tabloid whore" (film's own quote). Such a person loves "profits", not just "revenge with profits." (00:31:00 - 00:43:00)
His Last Vow - S3-E4
Factual error: Sherlock takes pains to explain in detail that he will deliberately corrupt the magnetic code stripe on an access control card he intends to use to enter the elevator to the villain's penthouse, by carrying it next to an operational cell phone. (This is possible due to the low frequency magnetic field from a phone's vibration motor.) But when he actually goes to access the elevator, he simply touches his access card to the reader instead of swiping or inserting the card through a slot, which is how a magnetic stripe reader would operate. The elevator uses an RFID proximity reader, not a magnetic stripe reader - a phone wouldn't corrupt an embedded RFID tag.
His Last Vow - S3-E4
Other mistake: The helicopter that takes Sherlock and Watson to Magnussen's house is the same one Mycroft arrives in later. Tail number G-VGMG.
His Last Vow - S3-E4
Continuity mistake: In the scene in the lab where they're testing Sherlock for drugs, Sherlock stands with his arms folded, then down, then folded, then down. Molly goes to reproach him, his arms are folded. The slaps somehow happen with his arms down.
His Last Vow - S3-E4
Continuity mistake: When Sherlock is being rushed to the hospital, when the paramedic rips open his shirt the body has body hair, but all the topless scenes following show that Cumberbatch has a hairless chest.
His Last Vow - S3-E4
Continuity mistake: When the surgeons revive Sherlock, the tube/string holding his breathing tube changes positions multiple times.
Continuity mistake: Sherlock turns over the note on the body to read it, then puts it back down face up. When Watson goes to look at it, it is face down again. (00:50:10 - 00:50:35)
Continuity mistake: After Sherlock repeatedly tells Culverton that he doesn't want to die, in the closeup Culverton increases the dosage with his right hand, but when it cuts to the wideshot he's doing it with his left hand.
Revealing mistake: When Molly's phone is ringing, the display shows the call has already begun.
Chosen answer: That line of dialogue has never actually been spoken in any of the Sherlock episodes, during seasons 1-4. However, that line is written in someone's fan-fiction story online, where it's said by Sherlock and directed at Anderson.
Super Grover ★