Hi Everyone, many thanks for your kind comments.
Roger, you are actually quite correct.
I did a spectral analysis of the first few notes shown here:
https://app.box.com/s/j2l7t3k6hsaw7j3v9cg04pr8odqatm7s Time is along the horizontal axis (left to right) and frequency is on the vertical axis, increasing as you go up. The first 5 notes are indicated with vertical arrows and labelled 1 to 5 and the opening E note with a horizontal arrow. the short second note has no label, but clearly occurs at the same frequency as the B at note 5. So I reckon that Hank probably started with his index finger already on the B, played the opening E with a strong down stroke and then caught the B with the following upstroke.
Well spotted! If i can manage to get enthusiastic I might drop it in.
Paul.