Strictly speaking, Vaughan Williams didn't "collect" the song from Mr Shergold; the credit for that is due to Dr George Gardiner (text) and J F Guyer (tune), 21 June 1906. RVW re-noted the tune in January 1909 prior to its publication in the Journal of the Folk-Song Society (III.4 (13) 1909, 285-6).

He did the same with several tunes from the Gardiner collection (in some cases from phonograph recordings) that the editorial board were a little unsure of for one reason or another, and sometimes gets credited as the original collector rather than, as it were, musical editor. I think that, in some cases, only his notation survives; which of course adds to the confusion.