It's no flaw that Nintendo can resolve. A corrupted game is caused by the user not by a miss function of the game or handheld device.
The game has been tested plenty of times before it was released. If it would be a common problem than half of this forum would have encountered a corrupted game by now. If you use your game for what it was intended for, and don't mess up the saving cycle, you will be absolutely fine.
Save and Quit. Wait for the AC:NL screen to appear, press Home, and end the power when you are back at the DS Home screen. If you are stuck in a saving cycle while trying to visit someone Resetti will appear in 2 or 3 minutes and will bring you back to before you entered the train station. You can also consider turning off your WiFi which will also bring Resetti since you lost contact with the internet.