Revealing mistake: The can of "Chernobly" is supposed to be from Moscow, and the lettering on the can contains at least one Cyrillic letter. However, the name printed on the can is nonsensical, using random Latin and Cyrillic letters in an effort to look Russian, but the letters don't spell a word and means nothing in Russian.
Revealing mistake: While Jacob is playing Second Life in the beginning of the movie, shortly after the four-minute mark, the camera briefly cuts to the screen of his laptop and shows the controls for the video player they used to play back the captured clip. Additionally, in the same shot, the menu bar at the top of the screen implies a Macintosh computer, while Jacob is using an Alienware PC. (00:04:09)
Chosen answer: The James Bond film "A View To A Kill" came out the year before in 1985. In the film, Bond's snowscooter is blown up by the Soviets, so he takes a wrecked ski from it and improvises it into a snowboard. Snowboards existed at the time, however, it wasn't until that film that their existence became well known. One year later in 1986, they'd still be very rare, but it's likely that his wasn't the first that the ski patrol had seen.
Captain Defenestrator