I'd imagine this is a fairly easy mistake to make, albeit one of those head-slapping "oh my god" fallacies that one would try pretty carefully to avoid if one knew there were more than one town named "Sydney" on this Earth.
Technology can certainly make planning air travel (slightly) easier, but not when you check your common sense and organic brain power at the gate. A twenty-one year old German tourist planned to take a trip to Sydney, Australia, but wound up 8,077 miles off-course — headed instead for the small oil town of Sydney, Montana, after mistyping his destination into a flight booking Web site. The man didn't notice anything was wrong until he was about to board a flight from Portland to chilly Montana, dressed in summer vacation clothes. Not only did the man trust the website a little too completely, his mother didn't notice the mistake because she trusted her son's techno savvy, saying he was "usually good with computers." Good with computers perhaps — but apparently not so good at the simple task of actually reading his itinerary.