Lyricist Sir Tim Rice knew Freddie well and he agrees with her explanation.
"It's fairly obvious to me this was Freddie's coming-out song," said Sir Tim.
"I've spoken to Roger Taylor [the band's drummer] about it. There is a very clear message in it. This is Freddie admitting that he is gay.
"In the line "Mama, I just killed a man" he's killed the old Freddie, his former image," says Sir Tim.
"With "Put a gun against his head, pulled my trigger, now he's dead" he's dead, the straight person he was originally. He's destroyed the man he was trying to be, and now this is him, trying to live with the new Freddie.
""I see a little silhouetto of a man" - that's him, still being haunted by what he's done, and what he is.
"Every time I hear the song I think of him trying to shake off one Freddie and embracing another - even all these years. Do I think he managed it? I think he was in the process of managing it rather well.
"Freddie was an exceptional lyricist, and Bohemian Rhapsody is one of the great pieces of music of the 20th Century."
Lesley-Ann Jones put the theory that Bohemian Rhapsody was a confession about his sexual orientation to Freddie in 1986. The singer laughed, then fell silent, before answering: "Bad timing!"
But the writer says her interpretation was confirmed by Freddie's lover Jim Hutton after Mercury's death - aged just 45 -from an Aids-related illness in November 1991.
She says Hutton told her: "You were right. Freddie was never going to admit it publicly, because he had to carry on the charade about being straight, for his family. But we discussed it many times.
"It was Freddie's confessional. It was about how different his life could have been. How much happier he would have felt, had he been able to be himself. The world heard a masterpiece of imagination. It was so intricate, and had so many layers, but its message was simple."
Bohemian Rhapsody was 'Freddie as he truly was', said Hutton.
- Mail on Sunday
