Continuity mistake: When Sophie asks Silas on the plane if he murdered her grandfather she takes the tape off his mouth for him to answer, but when it cuts to the window where they all look out, you can see Silas in the background with the tape still covering his mouth.
Continuity mistake: After Sophie and Robert exit the church they run through a group of nuns. Depending on the angle the nuns are either grouped together, spread apart, or walking in different distances between each other.
Answer: Tom Hanks NEVER said that Sophie wasn't in the car crash. What he said was that her last name was really "St Clair" (The same name as the family that died), and the press reported her dead as well. The man she called her grandfather wasn't really related to her, he just took care of her and gave her his name. That is why she could find no records of her family's death, she was looking for the wrong name.
Soylent Purple