The (glaring) problem is use of the word true to modify the word event. My Standard College Dictionary (Harcourt & Brace) defines an event as follows: "event n. 1. Something that takes place; a happening or an incident: the events of that period; especially an occurrence of considerable importance: historical events." This first definition might lead one to conclude that a happening must have been real in order to be considered an "event," as opposed to a fictional (made up) occurrence. But wait! The definition continues: "2. An actual or possible set of circumstances; a real or contingent situation: in the event of failure." Does this mean that the word event may be used to describe fake occurrences???? No. It means that an event can be hypothetical, for, you know, educational purposes.
Can't we go back to the halcyon days of "inspired by a true story?" Even "actual events" is better, because it at least suggests that events may be completely made up. In any event, Denzel can do whatever he likes, but Chris Pine has to stick to the (Grammarsnot) script.