If I were a betting man I would assume he started this exercise with the final assumed location in mind, and worked backwards from there to show how it could have been done.
That's actually what he was implying in his last tweet:
> The press conference to reveal the aircraft was held here last week so we can confirm the location. A guess likely would have landed someone in the same location but fun anyway to star match. I'm sure this entire process could be done with just stars and no google maps as well
> The press conference to reveal the aircraft was held here last week so we can confirm the location. A guess likely would have landed someone in the same location but fun anyway to star match. I'm sure this entire process could be done with just stars and no google maps as well