... So JW's dad is saying JW told him, via text, that LS was staying home and going to sleep. HT is saying that JW was planning on getting together with LS that night. So if LS told him she was staying home and going to sleep why would he think they were getting together later?
I first thought that LS might have left her phone at the bar because she was to intoxicated to remember it. But what if, since the game ended at 12:30 and JW didn't go to sleep until 2:30, he was texting her for two hours and CR thought she was being bothered by JW's texting and took her phone away from her. They both left forgetting about the phone on the bar. Just my opinion thinking out loud.
I personally think LS left her cell because she didn't remember it, given her description at SW not that much later. But it's also possible that she put it down somewhere (sand volleball court?) because she didn't feel like being tied to it that night. There's no way to really determine her mindset that night, IMO, i.e., did she or didn't she want to be in contact with JW. But if she needed a little space (and don't we all sometime?), maybe that was one way of getting it.
Or, as you speculate, CR could have stepped in and done it for her. But I don't think JW even needed to have been bothering her. She might have just not wanted to go home early but not wanted to explain so. JMO.