Hi Tom:
You can also check some of the threads here to see further confirmation of when Adorama received their first 18-200s from Nikon.
Yes, it's possible that Mr. Rockwell did receive a lens from another source. But, the discrepancy in dates and source is just the latest "inconsistency" from Mr. Rockwell.
If you consider Mr. Rockwell to be an authoritative source for objective "hands-on" camera and lens reviews, you're certainly not alone. My personal opinion is he too often feeds on those who want quick, easy and comforting answers.
Mr. Rockwell's own statements don't enhance his credibility in this regard:
"Don't take anything here (my website) as seriously as something you read scribbled on a bathroom wall. In fact, it's easier to put things on websites than it is for a vandal to write on a restroom wall."
See:
http://www.kenrockwell.com/tech/aboutrvw.htm
and:
"I never said any of this is true and I like to fool arond [sic] now and then and simply make stuff up."
See:
http://www.kenrockwell.com/tech/aboutrvw.htm
You would probably acknowledge there is a price to pay when you rely excessively upon someone else to tell you what is good and what is bad, rather than undertaking the more difficult task of seeking the facts, learning more about the area, and making your own critical evaluation based upon emprical standards. Ultimately, the issue has little to do with Mr. Rockwell, for the internet (and the world) is full of people who would convince us, rightly or otherwise, that we should let them guide us.
By the way, not "all of us" are fooled by him. And, not all of us are convinced that he respects his audience enough to care if the cracks in the facade are visible.
Best wishes for the New Year,
Tony