Factual error: The game "Timesplitters 2", which is being shown throughout the film, does not say "Player 2 has entered/left the game" on any system that it is released on, as shown at the start and end of the film. (00:04:25)
Factual error: The records that Shaun and Ed throw at the zombies in their garden shatter when they hit the wall. Only old fashioned 'shellac' records shatter like this -yet all the records were titles released after the introduction of "indestructible" flexible plastic records.
Answer: Shaun's last name is Riley. It can be seen on a poster ad from Shaun's DJ days.