I'm not sure specifically which 'denial true story' you are referring to. There could be many stories with that title or related to the concept of denial. It could be about someone denying a fact in a historical event, or perhaps a personal story where a person is in denial about something in their own life.
The movie Denial is based on a true story. It takes elements from real-life situations and transforms them into a compelling cinematic narrative. However, as with many film adaptations, certain details may have been embellished or simplified to make it more engaging for the audience.
It could mean that someone is denying something even though there is a real - life basis for it. For example, a person might deny their involvement in an event that actually happened and there is evidence for it.