Good thought. I've been wondering if she left the phone on purpose as an explanation to JW as to why she didn't hook up with him. But it sounds as though she was not in shape to be making rational, intentional decisions.
Now that's a fresh thought, and it might explain why JW was edgy to find her as well. If they had been texting, for instance, and then she left the phone, cutting him off, if you will. Still not sure why she'd leave the shoes ... she could have told him she dropped the phone or something. But that might have not been her decision.
Although phones are essential to most kids, I'm sure CR had one on him as well, so maybe she would have been ok with ditching hers for awhile? IDK ... her decision making does sound impaired, but maybe that would have been a decision she wouldn't usually make, if that makes sense.