The two nuclear plant operators, Mulder, Fowley, Gibson and other personnel walk into a radioactive nuclear plant without any monitors or protective gear. They all were not checked for radiation exposure -although that was not mentioned. Gibson as a special human, may not be susceptible to radiation but the others would be.
Too many errors in the operation, design, and function of a Nuclear Power Plant to list.
(at around 50 mins)The caption says Phoenix, Arizona, 5.46pm. But when the minibus drops the guy off at his house, the short shadow from the tall lampost on the left indicates that the time is much closer to midday.
At 31min, Scully holds the mobile phone to her cheek (far too low) and wouldn't be able to hear anything.
In the beginning the label says Phoenix, AZ and the landscape has Joshua Trees. There are no Joshua trees near Phoenix.
At around 26 minutes, when Scully and Mulder are talking in the motel room, Scully mispronounces the word corroborate, instead saying co-oberate.