As you might have read on the blog, the user query produces 2 underlying queries. The first targeting top users (having 10M+ followers). This one retrieves "Ryan Seacrest", even if the match was only part of the description. It would be better if replaced by a query targeting the user's followers, but I reached Twitter's rate limits while implementing it. The second targeting others.
If there's only a partial match with the description it probably shouldn't rank it so highly