Now, I've just realised something quite odd. We have all been saying things along the lines of "there was no need for Dylan to make his own way to his friends, as MR was coming back to give him a lift" and "why not buy what they needed on their way to dropping Dylan off" and we've all been doing the same thing - taking this arrangement as fact.
We've all just taken as gospel that MR said he told Dylan he'd be back to drop him off with his friends. And yet everything else he has said, has been disbelieved!!
So........ what if that isn't true. What if MR actually said "and when I get back from doing my chores, we're doing something together. I didn't pay all this money for you to come here just to disappear with your friends"? If that was the case, then Dylan could well have waited till MR left, then packed his bag with all his stuff and tried to hitch to his friends house. He'd have taken everything, as he had no intention of spending his week stuck at home with boring dad.
Or perhaps MR didn't really try to wake Dylan up. Maybe he thought that Dylan needed the sleep, and that he'd leave him and go off on his own to do his payroll stuff and intended to drive Dylan when he got back. But Dylan woke up, realised that he'd missed his lift, got angry and decided to go himself. MR doesn't want to admit he spoiled the plans Dylan made, as it might make him look mean, so he makes up the story about trying to wake him up and promising to drive him later.
With both of these scenarios, Dylan could well have avoided people - and hidden - if he didn't want Mark to find him and make him go home. He wasn't running away exactly, he was making his way to see his friends against his dad's wishes?
And as MR has bent the truth, saying he tried to wake Dylan up, then he wouldn't want to take a polygraph as he knows it would show that he wasn't telling the truth... even though he didn't actually hurt Dylan.