My theory goes along with LE knows CM left in EA's car, but they are letting him hang himself with lies waiting for that one piece to make a stronger case. They may or may not have video proof of her getting in the car. If they do, they may have profiled EA as someone they can't easily break for a confession if they show him that proof.
Pretty obvious LE considers EA a suspect, though LE never says so in such cases. They want perps to feel "safe" thinking they are clear so LE can watch them & hopefully catch them tripping up or leading them to evidence.
I think that no matter which way you look at it, CM was in EA's car. Otherwise he never would have lied about which garage he was parked in.
I also believe she was in the car when he passed the toll. Or he wouldn't have lied about which way he went.
The 3 minute or so delay in getting to the toll could be a few things. EA pulling over to try to make a move &/or arguing about where they were going. I don't think CM went back to the apt, except for a super quick trip to see if her keys were there, but I doubt that. Time to get to the apt, time spent looking around & time to get back to the car would have taken longer. I think the most likely scenario is they stopped at a gas station or such for a drink, snack, etc. Another possibility is they stopped to pick up one of the other party goers from the apt to get in the car with them.
Did CM go with EA willingly? IDK. She was clearly in the front seat (supported by LE removing seatbelt & EA wiping down passenger door). Did she have any phone pings after leaving SOL? I don't recall seeing that. If they stopped for anything as suggested above, likely willingly at that point. It could be unwillingly if the delay was because EA pulled over prior to the toll & something bad happened then.
I'm having a hard time correlating EA causing injury to CM in the parking garage, because I strongly suspect she was in the front seat. If he did, maybe he knocked her out & put her in the car. But that would be super risky driving around, unless he was sure the streets were deserted.
EA also clearly sustained his injuries after 4pm and before he arrived at Sprint the next morning. He had no limp on the video.
Barring other toll / GPS info, I believe CM is somewhere out there past the toll point.