This is the question that Vito asked Tom about Woltz. Tom said no, he was right, and Woltz came around.

But what if Woltz did have real balls? What if he reported the horse killing to his friend J. Edgar Hoover, hired Pinkertons to protect himself and his production, and began shooting his film immediately, without Johnny? Would Vito continue to try to force Johnny onto the production? Would he try to have Woltz killed? Given the looming challenge from Sollozzo, could Vito afford to delay his vengeance against Woltz, or would delay be seen as a sign of weakness, so that the other families would be more likely to follow Sollozzo's lead?