I've done a quick test on a database I have with a free-text index and the results of the query don't appear to vary depending on the order of words in the NEAR query. In other words the following two queries returned the exact same results in the same order:
SELECT * FROM DOCUMENT WHERE CONTAINS (Contents, 'health NEAR medical')
SELECT * FROM DOCUMENT WHERE CONTAINS (Contents, 'medical NEAR health')
So I would conclude there is no difference. This is backed up by the documentation that states:
"NEAR indicates the logical distance
between terms, rather than the
absolute distance between them. For
example, terms within different
phrases or sentences within a
paragraph are treated as farther apart
than terms in the same phrase or
sentence, regardless of their actual
proximity, on the assumption that they
are less related. Likewise, terms in
different paragraphs are treated as
being even farther apart."
Given that distance between two words will always be the same, regardless of order, then I can't see it would make any difference and my tests back this up.