The first part of the plan worked, but the second part didn't -- they never tracked down the guy who picked up the phone, but the fact that the phone was being used was enough to convince the police that he was still alive.
I guess the real lesson here is that simplicity is the best policy. His plan probably sounded brilliant in his head, but made too many assumptions about the way other people would behave.
(No one reading the article? what is this? slashdot?)
The author seems to think this was a good ruse, but I think I disagree; if I were an investigator, I think any coincidence, such as a cell phone accidentally left at a gas station, would be something I'd want to look into.
[ I'm assuming he didn't report it missing, because the article doesn't say so, and because it doesn't make sense that messages sent to unknown numbers from a stolen cellphone would mean that he's alive to investigators. ]