I would REALLY love to read the transcripts as well.
Visuals, I get it, it's easy to be deceived, but what about checking your NAVAIDs? Even during a visual recovery here at home field, I've got my TACAN dialed up, backed up with a waypoint offset to the initial. 10 DME would be fairly noticeable, and with two pilots, it's not like they're THAT task-saturated.
Visual illusions are a killer. That's why we emphasize them so much in training.
And judging distance is one of the hardest things to do--especially at night or in low visibility. That's why most operators have banned circling approaches under TERPS. It is quite easy to wander outside the protected area--and we have the broken metal and dead bodies to prove it.
Finger fires cause many problems. Too much head down messing with the box instead of just reverting to green needles and flying like you learned as a noob. When you look up and your brain doesn't agree with your eyes often the human tendency is to believe the eyes. That's when you can wind up landing at the wrong airport.
Maybe they were on a non-precision visual and the PF was looking outside thinking he had it nailed. Maybe, as someone mentioned above, they had the wrong airport in the box. All I know is that it can happen to anyone, especially if you're tired.
At the end of the day, the NFP has to back up the PF with the NAVs. Even then you can still screw it up.
When in doubt, go around. Sometimes that's the best option.
Unfortunately, if you don't recognize the error you're hosed.