Both the caption and the characters claim the brothers are driving on Interstate 35. The little two-lane road is clearly not an interstate, and a sign in the background shows "21 Texas - East".
When Sam comes out of the shower in a towel you can see that he has black shorts underneath the towel.
When they aren't able to kill the tulpa with their guns, Sam asks Ed and Harry if they published the "BS story" the brothers gave them. Sam had no need to ask them this since he saw the story on the website himself earlier that day before he and Dean went to the house to kill the tulpa.
When Sam and Dean are searching the basement of the haunted house, a close-up shot shows Sam's hand reaching around the cabinet door itself to open it. However, the next shot shows Sam reaching for the cabinet door's knob to open the cabinet.
Dean says that they cannot rely on the EMF meter in the abandoned house because the power lines still have some juice running through them. Which he is correct about, wires carrying an electric current would give false readings when looking for paranormal sources of electromagnetic energy. However in future episodes the brothers use EMF meters in homes that are full of electronic devices with no thought or mention of the fact that they would be generating false readings. In order for the EMF meters to work accurately they would need to cut the power to whatever building they were searching in.
Sam says that 'inverted cross has been used by Satanists for centuries, but this Sigil of Sulfur didn't show up in San Francisco until the 60's'. The inverted cross, also known as Petrine Cross (St. Peter's Cross) is a symbol used predominantly in Catholic imagery (although pretty rarely) since 2nd century AD. It's earliest use as in Satanist or generally anti-Christian context dates back to 1950's. The 'Sigil of Sulfur' as Sam called it, is really the Jerusalem Cross. (a cross potent within a circle) was, on the other hand, first found in Ancient Persian imagery and was later extensively used by Byzantines, its more elaborate. The true sigil of sulfur it a cross with two cross bars and a infinity symbol at the bottom. the sigil of sulfur is also known as the brimstone cross, the Leviathan Cross and the sigil of Leviathan.
The Tibetan "sigil" on the wall of Mordechai's house is a backwards Tibetan letter "ni"
There is no Collin County Public Library. In the Dallas-Fort Worth Area public libraries are designated by cities, e.g. Dallas Public Library, Plano etc.
At around 26:30 as Sam and Dean grab their coffee you can hear the person handing Dean, played by Jensen Ackles, say "Here you go Jensen." This is, sadly, not a goof. What the extra/server actually says @ 26:14 to Dean/Jensen is "Here you go, gents." Using the subtitles on Netflix or even the box set for Season 1 will verify this.
The Sheriff's Deputy cars and uniforms are completely wrong.
When Sam and Dean are investigating a sound in the basement at 19:30, you can see that the doors to the cabinet change position between scene changes. When Sam reaches out to open the cabinet, the door closest to him in the close-up is open more. But in the zoomed out shot, it's the opposite door that is more ajar.
The laughing fisherman and fish on the wall of the diner faces to the left when Dean pulls the cord and to the right when Sam pulls it.
At 26:20 when getting Coffee the barista hands over the coffee saying "Here you go Jensen" as he hands the coffee to Dean.
When Dean is given his drinks at the diner you can hear the server say "Here you go Jensen", instead of saying Dean.
Just after shooting at Mordechai with Ed and Harry filming behind them, Sam and Dean walk off looking around for the spirit. While the camera focuses on Ed and Harry talking about their video footage, someone's shoulder comes on screen from the right. Sam had headed left off-screen and Dean went through a door on-screen, so it could only be a film crew member.
(at around 27 mins) You can clearly see on the right hand side of the screen a camera man filming the paranormal investigators in close-up.
Basements are very rarely found in northeast Texas due to the high water table. If a house does have a basement it requires a pump to prevent flooding. An abandoned house's basement most likely would be filled with water and the contents destroyed or damaged.
They say they are in Richardson, Texas. However, Richardson is an Urban area that is part of the DFW metropolitan area (all concrete and asphalt). It is not rural like it is portrayed in the show.
When they were driving to Richardson, Texas, it showed I35 as a
two lane highway which is wrong and Richardson is on highway 75
not I35.