deGrasse Tyson's logic says that non-natural conclusions are arrived at 
entirely due to a lack of any known sufficient natural causes. According to this nonsensical viewpoint, those who concluded that Stone Henge was the work of intelligence would be arguing from gaps (ignorance). His mistake, and it's a mistake most Intelligent Design-denialists make, is his ignoring that non-natural causes (artificiality; design) can be 
very reasonably detected based, not on ignorance, but on 
knowledge. This knowledge is our understanding of intentional causation and the resulting pattern it creates. This pattern is 
complexity coupled with specification (referring to 
arrangement).
It's a completely uncontroversial scientific methodology.... until its  implications are considered unfavorable, in which case it goes from  uncontroversial to the purported most wild and crazy idea ever  conceived (I.D.).
  I.D.-denialist 
Carl Sagan uses I.D. methodology  in his two most famous endeavors: 
S.E.T.I. and 
Pale, Blue Dot.
The former, S.E.T.I., searches  throughout the (searchable) cosmos looking for anything deemed an  unnatural arrangement of signals (usually pulsars) which would almost  certainly signify intelligence. In other words, 
S.E.T.I. is 
attempting  to detect design via finding an appreciable degree of complex,  specified information) throughout the stoic cosmos.
In the latter, Sagan looks at the size and location of the Earth  relative to the size of the universe and deems that we occupy no  special (read: specific) place in the cosmos -- in other words, he's 
detected a lack of  design in the Earth's positioning via the absence of specification in its location amongst the universe.
What Sagan (and deGrasse) try to write off as pseudoscience (I.D.) actually follows perfectly logical, well-accepted scientific standards. The real reason they dismiss I.D. isn't because it's anti-scientific, but because they don't like its implications. The thought of the universe and/or life being designed by a Creator frightens them deeply, as it does with most atheists (or God-denialists, as I call them).
What they're doing is no different than what the fundamentalist Christian does when he rejects the age of the Earth. Rejecting science based on personal preference rather than the data. Sagan and deGrasse attempt to hide this behind strawman attacks, but those who are knowledgeable and posses critical thinking skills (such as myself) can see right through it, whereas those who lack knowledge and critical thinking (such as RidonKs and Take Your Lumps) cannot.
I've put both Carl Sagan and Neill deGrasse Tyson in their places and exposed their double-standards and hidden  agendas. Kudos to me.
For those interested, the 
I.D.E.A. Center further swats the "God-of-the-gap" myth (lie for Darwin?) out  of the ballpark... 
 
[FONT=Arial]FAQ: Is ID a "god-of-the-gaps"  argument?[/FONT]