Yes and it was still quite likely the correct choice/approach (how he went about it) in terms of the overall benefit to privacy globally (which seems to have been his aim).
Snowden could have attempted a few other legal approaches to being a whistleblower. The risk would have been far higher they would have buried him and the information in one form or another; they certainly would have tried. And even if he had succeeded through that channel, less information would have gotten out about what they were doing.
Doing something wrong doesn't always lead to a bad outcome or vice versa, there is no inherently fixed link there. Doing something right doesn't always lead to a good/positive outcome for example, that's one example I think more people can very easily relate to; and for the same reason that's true, the exact opposite is true.