I think it’s very believable that the Lyft driver watched her go over to the car and noticed the friendly nature of their greeting, simply because he was worried about her. He might have planned to wait, and if no one picked her up, offer her a ride to some safer place. (Sure, his time is money, but the time spent checking that she was safe would be an investment in peace of mind—and of course, he’d get paid if she DID need a ride elsewhere.)
I’d guess that LE isn’t talking because the man who met her is a major POI, (not saying that they know who he is, yet), and they don’t want him to know what they know.
All this MOO