The Post-Modern Prometheus - S5-E5
Continuity mistake: Izzy unwraps a peanut butter sandwich and sets it on a bare tree stump as bait for 'the Great Mutato', then he steps away with the others. When we see the Great Mutato hurriedly put it down, a paper bag is suddenly sitting on the stump beside the bitten sandwich.
Answer: As he stated many times throughout the series, Mulder needed Scully to be sober and skeptical. Whenever Scully's skepticism wavered and she started questioning her own rationality, Mulder would try to restore her sense of skepticism, because he needed her to be clear-thinking.
Charles Austin Miller