Board Thread:General Discussion/@comment-26261153-20150822013142/@comment-24674051-20150826195710

And we don't cherry pick. in-show is canon. If there is nothing in show to indicate one direction or another, then statements by Adam and Eddy are generally considered valid. However, we have had enough experience with the way that they twist words to know not to take statements at face value. I can't think of a time that they flat out lied (well, maybe the casting call for Rumple's Mom), but there have been multiple occasions where they said something that got interpreted one way by everyone, but was in reality something totally different.

As for Jefferson, Whale, and Will, there is some abiguity in-show that leaves it open to viewer interpretation how and why they were in Storybrooke. If you want to take Regina's statement at face value, I can't argue. But I don't take Regina's statement at face value, primarily because it has been shown that Regina does not totally understand the Dark Curse, and also because Regina can at times be prone to exageration of the truth.