N610ED
Hardly anything you wrote is true.
No wing "fell off" the aircraft. NTSB report says the entire plane except the left aileron were in the crash crater. The aileron was 3000 feet from the crash site.
No witness could have seen the "wing fall off in flight" because the the cloud ceiling was 1700 feet with "abundant cloud cover to 21,000 feet. Unless they were superman with x-ray vision, they didn't see anything until seconds before it crashed. It came down vertical at a high velocity (engines running it into the ground) from a high altitude.
The sheriff couldn't confirm anything. He isn't NTSB and all he knew was what he saw after the fact. So I don't get where you put so much emphasis on what the sheriff didn't see.
What ever happened, it wasn't from the plane coming apart midflight. It is more likely something happened with the pilot.