Automatic Transmission Gear Indicator problems of the 2008 Ford Focus

The contact owns a 2008 Ford Focus. Occasionally when the contact would place the vehicle into the park, the vehicle would continue moving forward as if it was not in gear. The vehicle was taken to the dealership where the contact was informed that the failure could not be reproduced. The contact noticed previously that the emergency brake would not stop the vehicle from moving whenever the failure occurred. The VIN was not available. The current and failure mileages were 29000.