A kid Sam's age would not be in bed at 7:00 PM.
The sheriff's car says police on it. A sheriff's vehicle would say sheriff on it.
Kate is tied up by the doctor by binding her wrists and ankles. When Tom goes to untie her, he unties her ankles, but she is able to pull her hands free without his help, indicating she was not really tied up.
Jess, played by Carol Alt mentions borrowing Kate's (played by Amy Jo Johnson) clothing. Alt at 5'-11" is nearly a foot taller than the 5'-2" Johnson, so they could not easily share any clothing.
The doctor pronounces the woman in the van as passing away due to a heart attack. She was still in the van with the airbag deployed. Such a determination cannot be made until an autopsy has been completed.
While at the crash involving the taxi, the sheriff had already begun to suspect an inordinate number of people were dying for such a small town. After the death of Mrs. White, he questions Kate's suggestion that the older residents were being murdered. Kate points this out to him.