Day 2: 10:00 P.M.-11:00 P.M. - S2-E15
Corrected entry: Not a mistake as such, just nasty on Mason's part. Jack's flying the plane on a suicide mission, and has a heart-wrenching final talk with Kim where he explains what's about to happen. Only AFTER that phonecall's finished does Mason pop out of the back of the plane and tell Jack to save himself. Seems a bit weird that he was sitting in the back chuckling to himself the whole time Jack was telling his daughter that he was about to die.
Correction: It's possible that Mason passed out during the flight and wasn't awake when Jack had his conversation with Kim. This makes sense since Mason isn't heard coughing again until after he shows himself on the plane. Jack is afraid to let Mason fly the plane because he might pass out again.