First of all, one of Search Engine Roundtable's first posts ever quotes Google's VP of Engineering on the Florida update. That was in December of 2003. Additionally, we have a plethora of linked threads later in December of 2003 about the Google Florida update, citing a date of November 15. The name "Florida" came from the WebmasterWorld thread which started on November 14, 2003.
So did the Guardian do their research? I don't think so. :)
And maybe the Guardian isn't a trustworthy news source, as Ian over at Sphinn adds:
If that's the UK "Guardian" newspaper then be aware they are known to the masses as "Teh Grauniad", due to their long history of spelling, grammar, and factual errors over the years.
Forum discussion continues at Sphinn.