Mulder: Deep Throat said "trust no one." And that’s hard, Scully. Suspecting everyone, everything, it wears you down. You even begin to doubt what you know is the truth. Before, I could only trust myself. Now, I can only trust you...and they’ve taken you away from me.
In this episode we see Mulder's sister being abducted while they are watching the television. But in the pilot episode Mulder tells Scully that Samantha was abducted out of her bed.
Samantha was calling Mulder, buttmunch in this episode. This is a famous expression from the show Beavis & Butthead which was aired in the 90's. No one from the 70's, should know about it.
Mulder's printer is a ink jet, but it makes sounds of a laser type printer.
A radio transmission with a wide bandwidth doesn't mean that the source is close by, but just that the transmission covers a lot of frequencies. A narrow bandwidth covers fewer frequencies.
Mulder's computer password is TRUSTNO1 which has 8 characters, but when Scully types it in, she clearly hits nine strokes and then "RETURN".
Since when does Puerto Rico have so many pine trees and evergreens? Location filming continues to plague The X-Files...