I wonder if he got turned around trying to get back to I-5 and backtracked thinking he was going the wrong way. For locals/those who've been to this lake, how easy would it be to get confused which way was back to the freeway? Particularly in the dark and possibly a sleepy or upset state of mind? (I'm assuming he was upset or at least preoccupied, based on him saying he had so much to talk to his Mom about)
From those quick truck stop places it's usually very easy and well signed, but sounds like this is further off the freeway and possibly more confusing to get back? Although in that case the camera should show him going away from the lake at least once, I guess... darn it. Still a thought, though.