Never Give a Trucker an Even Break - S1-E9
Continuity mistake: There is a scene where the female trucker is driving her truck and she intentionally hits a brown car. The problem is that she had already passed by this brown car a few seconds ago when David was getting into her truck through the window.
Never Give a Trucker an Even Break - S1-E9
Continuity mistake: When David is in the telephone booth trying to call the police he mentions that he can only read the first few digits of the phone number. Then there is a shot of the center of the dial which is almost all black and we cannot read any digit. A few seconds later another shot shows the center of the dial which is now white and we are able to read the first few digits.
Answer: An illness, although it's never stated what kind of illness. David blames his dad for her death because his father never took her to the hospital. So in all likelihood, her illness was never diagnosed anyways and David might not even have known what it was.
Bishop73