In 2010, a judge in Australia ruled the flute solo in the song sampled parts of Kookaburra Sits In The Old Gum Tree, a tune written by a music teacher for the Girl Guides in 1934, and ordered Hay and fellow composer Ron Strykert to hand over their royalty payments.

They subsequently lost an appeal in 2011 which ended the long-running legal battle over the song, but the case took a tragic turn a year later (12) when Greg Ham, the musician who played the disputed flute solo, was found dead at his home in Melbourne, aged 58, after suffering a heart attack.

Hay also lost his father Jim during the legal tussle, and he is convinced the stress of the case contributed to their deaths.

Speaking in a documentary about his career, titled Waiting For My Real Life, Hay says, "He (my dad) knew that when I wrote the song that there was nothing appropriated from anybody. He was incensed. Smoke would come out of his ears... He was getting older, he was getting stressed. I can't make any claims that this (court case) was the reason that he died, but I do feel instinctively it contributed to knocking him off his perch... Gregory (Ham) felt terribly guilty about having played the line, unconsciously or not, he goes downhill and can't seem to conquer whatever demons were going. And he goes, he dies. It's blood, it's people you love who you're losing over this litigation."