'622' in answer to one part of your question....
X-47B makes first carrier trap 11 Jul 2013 Dave Majumdar
"The US Navy made aviation history on 10 July when a Northrop Grumman X-47B unmanned combat air system-demonstrator aircraft made a first-ever arrested landing onboard the aircraft carrier USS George H W Bush, which was sailing some 70 miles (113km) of the Virginia coast....
X-47B makes first carrier trap - The DEW Line
The VIPs including SecNav I believe were onboard having arrived in the prop job.
Otherwise I would guess that because this is not a crab evolution nor a crab pilot attempting to deck land that there is a no worries blind faith due to the excellent testing scenario right from the getgo. No?
The technology that enabled this accurate landing (previous series of touch and goes etc.) is still under development for mere mortals - which - amongst other things is called JPALS.