A explicação que eu ouvi em alguns lugares foi que Prowse estava brincando / especulando na época, e só aconteceu de estar certo. Eu vi algumas pessoas especularem que ele deve ter visto um script ou rascunho inicial e corrido com isso.
Apesar de esta entrevista de 2006 não abordar especificamente o suposto vazamento, ele faz dizem que ele não sabia a verdade, e que ele sentiu que o estúdio não confiava nele porque ele poderia vazar algo assim.
So they never told you?
I finished the film in November 1976 and when it came out in the USA in May 1977 I got a note from director Russ Meyer saying ‘congratulations Dave, you’re in the biggest movie ever. By the way, did you know they overdubbed your voice?’ I have never spoken with George Lucas since 1983 and neither he or anyone from Lucasfilm has ever come to me saying why they overdubbed my voice.
In the Empire Strikes Back you also didn’t know the line ‘no Luke, I am your father’ was going to be in the movie. You said ‘No Luke, Obi-Wan is your father’.
No, I never said that. I just said ‘come and join me and the Dark Side’. I had no dialogue referring to Luke’s father. I have never seen a script for the Empire Strikes Back or Return of the Jedi. Everything was kept a secret because they were afraid things would leak. I think only George, Gary Kurtz and Mark Hamill knew.
What do you think about the fact that Darth Vader is Luke’s father?
I think it’s a wonderful twist.
And what about the fact that they didn’t tell you?
I think it’s a lack of trust. They were afraid I was going to say something in an interview. While if you’re one of the main characters the last thing you would do is give such information away. I was very careful so I hated the lack of trust.
Além disso, de acordo com este artigo , O próprio livro de Prowse afirma que ele só aprendeu sobre a reviravolta na estréia do filme. Ele repete isso em esta entrevista / artigo
Nos Annotated Screenplays, Irvin Kirshner, o diretor de The Empire Strikes Back também diz explicitamente que Prowse não sabia, e que Hamill era o único que sabia.That was not the only time he was kept in the dark.
David had no idea he would be revealed as the father of hero Luke Skywalker in the second film, The Empire Strikes Back, until he saw it on the big screen.
Security was tight around the scripts after information leaked out early in filming and Lucas may have wanted to keep the film's big twist closely guarded.
"They must have given me some completely different line, because it was all going to be overdubbed," David said.
"When I went to see the movie I suddenly discovered I was Luke's father.
"That's my favourite scene of all."
The actor who played Vader did not know that Luke was his son; when we did the scene, the only one who knew was Mark, and I told him right before we shot it. We didn't want anybody to know, so i had the page with the real dialogue put away. So the actor playing Vader was saying other words; I gave him other words. He was saying something totally different, which of course we replaced later.