Factual error: In the beginning sequence where they show the sperm first fertilizing the egg, it is biologically incorrect - only the head part of the sperm enters an egg, everything else stays on the outside and eventually dies off.
Factual error: When Mollie and James are bringing "Grandpa" to his new old folk's home, the shot that shows the address of the place says "Yaletown, Cambie St." This is a Vancouver address, where the movie was filmed, although it's supposed to take place in New York.
