Character mistake: When Neal tells Rebecca about an Indian Idol and describes the idol to her, she tells him it's the Hindu Idol of Seeta, the goddess of wealth. Actually the idol is of Goddess Laxmi.
Character mistake: When the private investigator shows Castle and Beckett the VIP Liaisons website, "Liaison" is misspelled "Liason." (00:17:40)
Character mistake: When the wife of Lennie James (number 147) says to her husband 'You left the door open' (just after the incident with their daughter), this is wrong. Rewind a few minutes and you will see that there are 3 people: 6, 313 and 147. 147 leaves when his wife says 'Cake's out of the oven!', leaving 6 and 313. 313 leaves, with 6 alone. Then Number 6 leaves the backyard with the door open. Even if she meant the door to the house, he would have to go through it last.
Character mistake: Steffan addresses his brother, Daemon, as "Steffan" at The Grill after Ellina talks to Steffan about the crystal that plagues Bonnie with nightmares about Emily. (00:15:06)
Suggested correction: You missed the point of the scene. They were imitating each other. Stefan was pretending to speak as Damon. Damon replies with "I don't, Damon" and then "you're really hard to imitate".
Character mistake: When April goes to see Hank at his motel, he states her romantic feelings for him are a result of "Nightingale Syndrome," however, the Nightingale Effect is caused by the caregiver developing romantic feelings for the patient, not the other way around.