Continuity mistake: When Scott runs into his room after the party the shadow of the blinds can be seen all the way across the room, but in the next shot of the window, the blinds are only halfway down. The shadows cast doesn't match.
Continuity mistake: When Derek finds the note on his car it's snowing, in the next shot it's not.
Second Chance at First Line - S1-E2
Continuity mistake: When Allison opens her locker, the things inside change from shot to shot.
Continuity mistake: When Scott loses his asthma inhaler, we see it fly out of his hand and land on the ground and it is a light khaki colour. Later on, when Scott and Stiles go back to the woods in the day to look for the inhaler, they come across Derek and when Derek throws Scott his inhaler, it is a white colour.
