Character mistake: On the train Otto says a 1964 quarter is pure silver. They are actually 90% silver and 10% copper. (00:30:28)
Suggested correction: Most people wouldn't know the chemical make-up of a quarter prior to 1965. They'd just refer to it as a silver quarter, not realizing it's partially comprised of copper.
Continuity mistake: Near the end of the movie, when Otto is holding the baby, the baby's hat is on and off in between shots. (01:48:48)