My point was that if OP's son is still terrified of getting lost, it might help him to have concrete plans in advance that come from an authority figure, including a plan that doesn't rely on having a specific device, charge, and signal each time. The specifics of whom to approach are up to the parent and child - I'm just giving one example.

Also, I think "victim blaming" isn't an apt term in this case. Getting lost is almost never caused by someone being victimized, it's caused by lack of attention and then lack of a way to resolve the situation on your own.