Factual error: As Millie gets out of the car, she is greeted by an Italian who addresses her as "signora" ("madam"). In Italy, young women are addressed as "signorina" ("miss"). (00:30:15)
Factual error: The bus' horn makes a sound like a truck's klaxon. A London bus horn is higher pitched than that. (01:07:10)
Factual error: Shortly after David and Griffin jump to Japan, Griffin goes to a car dealership and takes a Mercedes. Griffin then drives on the right side of the street rather than on the left as he should in Japan.
Answer: In the novel that this movie was based on, his mother was killed and David does go looking for the man who did it. Those doing the summaries are just confusing the two different versions.