Hibbing 911 - S10-E8
Revealing mistake: Sam types the address Donna gave him into an untitled note, which is supposed to act as a Maps search engine. A second later, a map with the address pulls up. His phone also says it's 9:56/9:58 a.m. (00:31:15)
Continuity mistake: As Sam is looking for the next victim in his visions, she walks by with her baby in a stroller. The baby is a completely different looking doll the first two times shown, but is blue-eyed Rosie when Sam approaches and interacts with her. (00:12:30)
Other mistake: In the original "Scooby-Doo" episode from which this episode is taken from, the house for the reading of the will was on an island as the Mystery, Inc. gang travelled to the house via motorboat. In this episode of "Supernatural", Sam, Dean, and the Mystery, Inc. Crew merely drive up to the house.
Character mistake: Sam describes the books as being from "pre-Biblical lore" and then says they are written in Aramaic. Aramaic was a language during New Testament Biblical times and didn't exist in pre-Biblical times i.e. prior to 4000 B.C.E.
Suggested correction: I believe he meant the book "contained" pre-biblical lore.
Bloody Mary - S1-E5
Continuity mistake: When Jill's friend is saying how Jill died and mentions her eyes, she has her hands lowered in one shot but raised in the next. (00:16:11)
Continuity mistake: When Dean says he's going to talk to Amanda to get a grip on her mental state he has his head back on the seat and is looking straight ahead. When the shot changes he's now looking at Sam. (00:27:20)