When Amanda breaks Cecilia's roof, causing the glass to hit the floor Cecilia was standing on, Cecilia was on the bottom floor with a regular roof. The glass roof was on the floor above.
When John is shown buying a bottle of tequila, the store has signage referencing apps like Amazon and delivery service Rappi. Apps of the type did not exist in 2001, which is when this film is set.
Set in 2001, John has a Gmail account. Gmail didn't exist until 2004.
Cecilia and Amanda are shown using a white Blackberry Curve 8520, which was released in 2009. The film is supposed to take place shortly after Saw (2004), which happened in 2001.
John is offered a tequila, Código 1530, which did not exist in 2001.
Despite being set in 2001, after John lands in Mexico City's airport, the Metrobus in Reforma is shown; this did not exist at the time.
When John speaks to Carlos, he does not understand any English. However, when Cecilia invites Carlos inside, he understands what she is saying and says "ok".