Here's the passage I referred to:

"… the sea shanties, which Bert and MacColl pioneered on the British folk scene… and which the folk audiences assumed to be authoritative because of Bert's whaling trip (!) were, according to Britain's last genuine shantyman, and nautical authority, Stan Hugill, somewhat less so:

All the weird shanties they put over are good, perhaps, depending on which way you look at them. But for Bert they had to be modal, they had to be Mixolydian, they had to be Dorian. They never sang the songs the real sailors sang: 'The Rio Grande', 'Shenandoah', 'The Banks of the Sacramento'… Those were the songs the sailors sang but they never looked at them. Bert did 'Sally Brown' but not the normal version, not the way any sailor ever did it. He sang a Bahamian boatman's rowing song as a deepwater shanty, but it was never sung in deepwater. It was only collected once in the early '60s but Bert's version had extra verses that he must have written. 'Little Sally Racket' came from a collection of Jamaican folk songs and, again, was not the version sung by sailors."

In his endnotes Dave Arthur gives the source only as 'Stan Hugill interview'.

My description of Hugill as a 'pedant' was actually ironic. I was just a bit surprised to find 'Lighter' (whose posts I always enjoy and respect) suggesting that one has to be a pedant even to notice - never mind care about - Lloyd's editorial interventions. As it happened I'd been reading that passage in 'Bert' just a couple of days ago, and it popped into my head.