My husband, who has shot a 50 caliber machine gun, aka "Ma Duce", during the Vietnam War agrees with you. He knows the bullet can go that far or farther but hitting a human target or any target for that matter had to have been pure luck. In fact, my husband would like to take the sniper to Las Vegas with him. 
My son served nine and a half years as a Marine, shot various firearms, and other "neat" things that go boom and blow-up such as $5,000 missiles, as a Marine Anti-Tank Assaultman and in the Advance Infantry Assault team, said many "improvements" and "innovative" weapons have been developed, since his last tour in Iraq.
There are so many things these days that were once the stuff of comic books that are now reality. Jet packs, IPhone watches (remember Dick Tracy?), unmanned flights and driverless cars to name a few. So, while unlikely, it is possible that a scope and some type of computer programmed sniper rifle has been developed. 
Guess we could ask Marine Gunnery Sgt. Lee Emery