Anachronisms

One of Kennedy's advisers uses the term "as pure as Mother Teresa." Although the BBC aired a documentary in the UK on Mother Teresa in 1969, it was not until 1971 that the US knew of her work through the book, " Something Beautiful for God."

Factual errors

The movie depicts the moon being full on the night of Kennedy's crash; in reality, the moon was full July 29, which meant that it would have been a waxing crescent on the night July 18.

Factual errors

Although Bruce Dern makes a powerful (albeit mostly mute) appearance in the film in the role of Joseph Kennedy Sr., Ted's mother Rose is not depicted at all. What a strange decision to utterly omit her in the interest of tight storytelling, given the significant presence she surely must have been during those days.

Anachronisms

The exterior door used in the movie as the home of the Kopechnes is a fiberglass model with an oval glass insert with brass caming. This style of door didn't exist until the mid 1980s.

Factual errors

The car Ted Kennedy was driving at Chappaquiddick was a 4 door sedan with center pillars behind the front doors. The car in the movie is a 4 door pillarless hardtop. .

Plot holes

If Ted Kennedy was able to get out of the car that means that the door (or window, it was summer) was open. If the door was open Mary Jo Kopechne had a possibility and enough time (despite of panic) to get out of the car too. Maybe she was unconscious because of the impact? However, neither movie nor official investigation did not pay attention to those questions and hypothesis.