Cubs Fan

Chosen answer: There's no particularly good way to tell - one good rule of thumb is to consider which events the police would be able to quickly check themselves. So, for example, Verbal's description of the attack on New York's Finest Taxi Service would have been substantially factual, as he wouldn't want to risk contradicting anything that the police might have found out from witnesses. Likewise the deaths of Saul Berg and his bodyguards would be largely correct. The most likely scenario is that large parts of what Verbal says are reasonably close to the truth - by doing that, it would make it easier for him to stick to a consistent story.

Tailkinker ★

Answer: There's a plot hole there though. Verbal basically tells Kujan that it was he who shot Saul. He's basically confessed to murder, which would surely change the situation? Why not just say Keaton shot Saul?

Answer: I believe everything is factual up to the point they go to L.A. Agent Kujon confirms the lineup and taxi service bust.