Bem, isso tem sido uma fonte de controvérsia, alguns dizem que foi Tim Miller ou alguém próximo a ele no Blur Studios, mas na verdade pode ter sido o próprio Ryan Reynolds:
Podemos finalmente saber quem vazou a imagem do Deadpool
While Miller hasn’t publicly said he was behind the leak, numerous sources point to him or one of his colleagues at Blur. I have no smoking-gun proof other than my typically very reliable sources on such matters. But if so, it was a bold move from a filmmaker who had nothing to lose and everything to gain.
Ryan Reynolds declarou em uma entrevista em The Tonight Show com Jimmy Fallon que foi uma das 4 pessoas, ele, Rhett Reese, Paul Wernick ou Tim Miller, mas pode ter realmente foi o próprio ator que vazou:
We developed the script 6 years ago, wrote this fantastic script , it leaked online and Deadpool fans went nuts for it. So the studio granted us a small amount of money to make a test footage that we shot, which then sat on the shelf for 4 years as it does and they did not do anything with it, as it does and just under 2 years ago it leaked accidentally onto the internet... Well here is the thing, the deadpool fans freaked out and overwhelmed Fox and Fox basically had to green light the movie, the problem was that the footage was owned by Fox and sort of illegal that....I know that one of us did it, there me (Ryan Reynolds) Rhett reese, Paul Wernick, Tim Miller the director, one of us did it. We said that someone should leak it.