He can't do some drone work to check out the progress on the armory roof. Totally illegal.

From: Busting Myths about the FAA and Unmanned Aircraft

Myth #2: Commercial UAS flights are OK if I'm over private property and stay below 400 feet.

Fact—The FAA published a Federal Register notice in 2007 that clarified the agency's policy: You may not fly a UAS for commercial purposes by claiming that you're operating according to the Model Aircraft guidelines (below 400 feet, 3 miles from an airport, away from populated areas.)  Commercial operations are only authorized on a case-by-case basis. A commercial flight requires a certified aircraft, a licensed pilot and operating approval. To date, only one operation has met these criteria, using Insitu's ScanEagle, and authorization was limited to the Arctic. (FAA opens the Arctic to commercial small unmanned aircraft)

Myth #3: Commercial UAS operations are a "gray area" in FAA regulations.

Fact—There are no shades of gray in FAA regulations. Anyone who wants to fly an aircraft—manned or unmanned—in U.S. airspace needs some level of FAA approval. Private sector (civil) users can obtain an experimental airworthiness certificate to conduct research and development, training and flight demonstrations.  Commercial UAS operations are limited and require the operator to have certified aircraft and pilots, as well as operating approval. To date, only two UAS models (the Scan Eagle and Aerovironment's Puma) have been certified, and they can only fly in the Arctic. Public entities (federal, state and local governments, and public universities) may apply for a Certificate of Waiver or Authorization (COA)

The FAA reviews and approves UAS operations over densely-populated areas on a case-by-case basis.

Flying model aircraft solely for hobby or recreational reasons does not require FAA approval. However, hobbyists are advised to operate their aircraft in accordance with the agency's model aircraft guidelines (see Advisory Circular 91-57). In the FAA Modernization and Reform Act of 2012 (Public Law 112-95, Sec 336), Congress exempted model aircraft from new rules or regulations provided the aircraft are operated "in accordance with a community-based set of safety guidelines and within the programming of a nationwide community-based organization." 

The FAA and the Academy of Model Aeronautics recently signed a first-ever agreement that formalizes a working relationship and establishes a partnership for advancing safe model UAS operations. This agreement also lays the ground work for enacting the model aircraft provisions of Public Law 112-95, Sec 336. Modelers operating under the provisions of P.L. 112-95, Sec 336 must comply with the safety guidelines of a nationwide community-based organization.