From what I was able to tell, I think the finger vibrato is controllable. For instance, the low D didnt have any. And in the B section, there is a G note where it sounds like the vibrato starts, and then actually stops before the next F note. Also, there is a B-flat somewhere in the song that has no vibrato. I think the demo maker was just over-emphasizing the vibrato, hopefully; but that is what my ears were telling me anyway.