The person who contacted you may have found an archived Google page, which would make it irrelevant whether the status of the tree was changed later.
Also, back around 2009-2010 when all of this first started to get notice, I went on Mundia to check things out and discovered that they had posted all the Ancestry trees there, BUT identified with the tree owner's real name (not Ancestry username). I complained (very loudly!) and also made my tree private and even changed my official Ancestry "real" name to match my username, since Ancestry doesn't know or care what you say your name is, so long as the credit card charge goes through, which it does.
If the archived page on Google had your real name on it from back in that period (which I understand lasted at least six months, if not longer), that could explain why the person could possibly track you down using various internet sources.
To doublecheck your trees on Mundia, create a new Mundia account using a new e-mail address that is not associated with Ancestry (e.g., a new Hotmail address, which is free). Then log in and do a search for names that should show up (especially unique names) if your tree is really there. Then you will know whether the person just found a residual image, or the tree(s) really still can be found through the current Mundia site.