Plot hole: If the Lady of the Lake walks every night to her room and kills those in her path, why didn't Flora and Miles' parents die in their room by the hands of the Lady in the Lake when they first moved in?
Other mistake: At the end, when the reflection of burned Lucy still shows her beautiful, Dracula's reflection shows him as he is seen; not old and ugly as in his usual mirror reflections.
Sacrificio - S1-E8
Factual error: Paco commandeers a new model Audi Q5 or Q3, the model badge is missing from the rear of the vehicle but it appears to be the larger Q5. He breaks a window and without a key he hot wires it. It is technologically impossible to hot wire newer model cars such as these. The only way to steal these cars is via computer software and computer attached to the diagnostic plug, or another key which contains a micro-chip. (00:56:00 - 00:57:00)
Factual error: In Massachusetts, Atticus, Leti and George are attacked by the local sheriff and his deputies, who are patrolling the county roads. In Massachusetts, sheriffs run the county jails, but they do not (and did not) handle routine policing, which is the responsibility only of municipal police departments.
Factual error: Despite taking place in Massachusetts and many of the cars having Massachusetts license plates, none of the vehicles has the required annual inspection sticker on the lower part of the passenger side of the windshield.