Here is what Apo said about the Big Lie:
"This is not to say Steven is completely without fault for sitting where he is today. The evidence in this case will be - probably to a nauseating degree - that Steven Capobianco lied to Detective Loo from the very start regarding his knowledge and/or involvement with Carly's disappearance and ultimately her death. Regarding this lie, this trial will finally address why Steven, and any other reasonable person in his shoes, would lie to a detective questioning you for something that is, for all you know, smaller than what you're trying to hide with the lie. Regarding this lie, the evidence will show that Steven provided the most information that he could, in relevant part, to Detective Loo and other investigators. The evidence will show that Steven did his best, under the circumstances, to provide Detective Loo with what he knew about the last whereabouts of Carly, all the way to the point of placing them on the road in the area he last saw her. In irrelevant part, the evidence will show that Steven refused to gratuitously incriminate both he and Carly by telling the whole truth about the night of February 9, 2014. That evidence will be coming out in trial. Ladies and Gentlemen, most of the evidence presented by the state in this trial will be addressing the "big lie" by Steven Capobianco, even though ironically, this "lie" or "statement" would have proved helpful to the investigators if taken for informative purposes rather than for guilt purposes."
It sounds to me like Apo said to Steven "Listen brah, the prosecution is going to show with certainty that there was no broken down vehicle at Keanae. You sure there's nothing else you want to tell me?"
And then Steven confessed to Apo that the broken-down truck was a lie, and "admitted" that he and Charli were really out there for some more nefarious purpose that night, like a drug deal, but he didn't want to say it to the cops initially because it involved illegal activity.
Does anyone have any other interpretations, based on Apo's hints?