But why didn't he communicate with anybody on Monday? He never picked up any of his dad's calls or texts that morning. If his cell was broken, why not pick up the landline when his dad called that morning?
When my kids had problems with their cells, believe me, I heard about it immediately. I cannot imagine that his cell broke, and he didn't bother to tell Elaine or Mark in an attempt to have it fixed or replaced.
Especially when he was looking so forward to seeing all of his old friends. He would need a cell to make that happen smoothly.
I do not believe he went fishing all by himself, when he knew his friends were waiting to see him. He was a very social kid, and his texts to R are evidence of that. He was eager to see his friends---not to walk all alone to a remote fishing spot on a cold morning.
I also doubt highly that he tried to hitchhike that morning, without making contact or replying to his friends. That makes no sense because he does not even know where they would be at that time. Why would he attempt to hitch a ride but not even reply to R's morning text? And if his cell was broken, why not wait for Dad to return so he could get a new battery in town first?
I can believe he just stepped outside for a breath of fresh air, but then his belongings would still be at Mark's if that were the case.