"Contrary to the claim in the dialogue, Sharp did credit Louie Hooper, Lucy White and John England for all the songs they contributed to 'Folk Songs from Somerset'. There was no quarrel with Louie Hooper, who remembered Sharp very fondly after his death as a kind and generous friend. And he also paid her and her sister for their songs."

Perhaps, the complete departure from reality was the only way the playwright was able to build the edifice to deliver the payload. The playwright would have known that what they were writing was not true and this is the only explanation I can come up with.

I can see why you would be angry though. Luckily I did not know the facts until you presented them.