I work with nano-UAVs. I am very skeptical that the 40 minute flight time is even close to being real. Especially with a quadcopter design. They are way to inefficient.
Side note: the DJI Mini 1 is an excellent drone -- stable flight, great camera, and great range. I wouldn't be surprised if it outperforms this 'Bug' drone by most metrics, except for the critical (at least for military purposes) "not being made by a Chinese company" metric.