I totally forgot about that. It's always horrified me that this feature is out there on an app very young people use (rightly or wrongly), likely with people they don't know in real life. Scary stuff IMO.
I thought this too. Ear buds may also be with her. I think her body was disposed of as is - whatever was on her person, in her ears etc would be in the same place she is, unless something small like the ear buds fell out unnoticed. I can't recall if they were small ones that fit entirely in the ear or the ones that dangle down a bit. One's far more noticable than the other. I really don't think he's taken bits and pieces from her and disposed elsewhere, or kept them. Perhaps the phone was taken, as the possible immediate thought would be that she would have had a phone, and phones can track you, so must be disposed of. Maybe she had it out to record or call someone and therefore front of mind for the accused. I'd say, in a panicked and drug/alcohol state, he turned the phone off, thinking that problem was temporarily fixed, to worry about later. I'm definitely no tech head, and I don't know exactly what a turned off phone can and can't do, maybe he was the same - although it has been noted he was into STEM type subjects at school, from memory. However, phones are another beast, he may not have been all over them. Another thought is that the phone was concealed near the alleged murder site at the time of the alleged crime, and when he'd had time to think he came back for it.
What we do know is that Samantha's phone was not obliterated, it was kept with its case, and contained identification cards as well. Disposed of in fairly shallow water, very near the roadway, on private property.
Let's just assume it was the accused that disposed of the phone for this argument. These few facts indicate to me that this was more of a panicked, desperate act, and not well thought out. I think it was disposed of later that day, and accounts for the 5pm alleged ping. If you had time and privacy, and lived very near remote bushland or on a country property without people around, you could, and should, do your best to damage all those items enough so that if they were ever found, they would yield as little evidence as possible. I'd certainly cut up and/or melt down the ID, and most definitely not dispose of it with the phone, which I would have done my best to smash to smithereens. That would be my MO, but I'm not a murderer. I'm thinking he's either not very clever, and/or had limited time and opportunities to dispose of this one last item tying him to the alleged crime, and it was burning a hole in his literal pocket.