Character mistake: In the 7/19/19 episode, Rafe tells Gabi that, even if she can open the briefcase she stole from Xander, nothing she finds would be admissible in court as evidence, because it is "fruit of the poisonous tree." Rafe is a police officer, but he's wrong about this. The exclusionary rule only applies to searches by police. If a private citizen obtains evidence illegally, such as by trespassing or theft, it actually is generally admissible in court, although the citizen may be subject to prosecution for the illegal action.
Character mistake: In the 7/30/14 episode, Sami informs Kayla of Abby's indiscretion with hospital board member EJ and demands that Kayla fire Abby, or else Sami will cancel a large charitable donation. Sami gives Kayla an explicit choice, "either Abby gets fired or the hospital gets the donation." Sami is misspeaking here, because actually the hospital gets the donation IF Abby gets fired. Sami should have said "Abby gets fired or the hospital loses the donation" or "Abby keeps her job or the hospital gets the donation." (00:01:50)
Character mistake: On 7/5/11, Lexie says that Fay "wouldn't have had that heart attack if she hadn't been assaulted." Fay's eventual death was actually caused by somebody deliberately smothering her, although Lexie doesn't know that. However, as one of the doctors treating Fay, Lexie had concluded that Fay's death was caused by a stroke, not a heart attack. At that time, she also didn't think the stroke was related to her fall down the stairs.