Claudia's hair changes between curly and straight several times in the episode.
Rebecca St. Claire says that Roxanne's last name was Crane, but in the police report, it says that her last name was Backerly.
When Myka pulls the knife out of Petes hand you can briefly see his arm and hand are back to normal but in the next scene they are back to glass.
Raitt flips his magazine closed then after a cut flips it closed again.
The cover picture of "Where & When" Magazine was suppose to be from 1961. The picture was Jacqueline Kennedy at Shannon Airport, June 15, 1967. That is six years later, about four years after JFK died in Dallas.
The Butterfly Effect. Myka says, "What about the Butterfly Effect?? When you step on a butterfly in the past, it changes the whole future." That is not the definition of "The Butterfly Effect". The Butterfly Effect posits the possibility that, if a butterfly flaps it's wings in Tokyo, it creates thunderstorms in New York City. It's a theory that all things are interconnected to the point that small changes in one location (or at one point in the past) could produce large changes in a far away location (or far into the future).
In the 1961 magazine office, several IBM Selectric II typewriters can be seen. This model was introduced in 1971.
At the beginning of the street scene where Roxanne is killed, showing the street sign at the corner of Hoover St. and _rtola Ave, the white Ford Thunderbird is a 1963 model, but Pete & Myke have been sent back to 1961.
When Pete/Jack gets stabbed with the letter opener Myka/Rebecca just pulls it back out and P/J's hand and arm return to normal. When Beth gets stabbed they all act like there is no way to save her, when all they need to do is pull the letter opener out again and she will survive. Beth even says quite clearly " No, it has to stay in!"
Pete and Myka might have enough time to film their message from 1961, but they have a cine camera, not video. So it's now exposed film, not a processed 'movie' for a projector. Any exposure to light would destroy the information.