[jodrellblank]

Let me check that claim using a dictionary:

    mathematician /măth″ə-mə-tĭsh′ən/

        A person skilled or learned in mathematics.
    
        One versed in mathematics.
    
        An expert on mathematics. 
    
    The American Heritage® Dictionary of the English Language, 5th Edition • More at Wordnik

None of the definitions require creating or advancing mathematics.

[danielmarkbruce]

People in the field would never, ever call someone "versed in mathematics" as being a mathematician.

I don't even buy that regular people call someone who is "versed in mathematics" a "mathematician".

If you met a 30 year old person and asked what they do and they said "I'm an athlete" - do you take the dictionary definition there too? Most people will assume they mean a professional athlete.