The US Constitution, and the US Code written pursuant to it, do not define the term "natural born citizen".
Birthers like to repeat the definition of Vattel, which was surely known to Madison and the others, but repetition is not precedent.
Most Americans who voted on November 2, 2008 believed, rightly or wrongly, that NBC meant "born here". That belief was widespread as long ago as 1968 when George Romney (born in Mexico) was a candidate for the Republican nomination, and presumably before.
A court decision to change the effect of 69 million votes, after the fact, wouldn't happen and probably shouldn't happen.
I applaud efforts to define NBC in the US Code, but that will not occur while "Obama", whatever his real name is, is in office.
Your contention is ridiculous. Law either is or is not. If law is to be, it can ONLY be what the law says. If, as you contend, law is what is "assumed" or "believed", there is in fact NO law. Tell that to a state trooper that you "assumed" or "believed" that the speed limit was something other than was posted.