WD,
this stone "tool" looks indeed a little bit like an neolithic driller (not like a scraper as your friend described it) but this stone wasn´t made by humans. it is a natural form and those parts who looks like flintknapping, are just natural washed out areas of softer stone. I also don´t see any worn or used areas on it. I don´t think a human ever did something with it at all.
Hope you are not disappointed!!
Remembers me that I want to upload some pics of my neolithic collection (with description of the tools)