During the scene where the main boy has been taken to hospital after trying to kill his father, Mulder and Scully are set to meet in the corridor.

Due to some bad Directing and timing, both of there new positional markings can clearly be seen on the floor. Scully's is Red Tape, and Mulder's Yellow Tape (or the other way round, that bit doesn't matter).

The nurse that crosses between them was supposed to obscure the audiences view. But that didn't work!!