Visible crew/equipment: When Stone and Hall are in the van in Piedmont looking for the satellite, at the point right after Stone says "hold it, you need to back up and go to the left", at two brief instances you can see the large rectangular movie light reflected in the back doors of the van. (00:21:55)
Visible crew/equipment: When Stone and Hall fly over in the helicopter, the mark for the positioning of one of the 'corpses' is visible. There is a thick black line perfectly outlining the right side of the body. It's the one the camera centers on as Stone talks about the birds spreading the disease.
Answer: The government would have concocted an official story about what happened in Piedmont - attributing it to some natural disaster. The old man had dementia, was alcoholic, and suffered a severe emotional trauma, so it's doubtful many would give much credence to anything he had to say. He was also confined to a small area of the Wildfire complex and was given minimal information about what it was or where he was at. In his confused mental state at the time, he probably would have remembered little about what actually happened.
raywest ★