Everything you said is wrong in the technical issues.@LeGenD how does a stealth UAV with a service ceiling of 50,000 ft (and let's be honest it was flying at something like that level, certainly thousands and thousands of feet) just glide gracefully to the ground and sustain only very minor (almost un- noticeable) fuselage damage (and probably some broken gear if deployed)? Bearing in mind that flying wings are notoriously difficult to keep in the air and need constant FBW input just to keep them from going out of control.
To start off...A UAV with long straight wings is NOT a flying wing design. To see a true flying wing design, look at the B-2 and its predecessors.
Now...A UAV with long straight wings is essentially a glider when without power. In fact, there is a documented event of an F-106 that entered a flat spin, the pilot believed his situation to be non-recoverable and ejected, the jet self recovered, and landed itself.
Long straight wings are designed to maximize lift at most flight conditions, so yes, it is more than possible that an unattended UAV can land itself with barely any damages.