Correction: The FAA only said it was not a part of an airplane. The piece of iron could have been dropped from an airplane. The FAA ought to check their radar data to determine what planes both commercial and private where over the area.
Even if it was "dropped" from an aircraft, what would explain the heat of the object? People on the ground said it was too hot to handle for :30 minutes after it was on the ground.
There's not enough friction from an intra-atmosphere fall to generate that kind of heat. It certainly makes be believe that it came from above the exosphere.