Damn, tough call. I'm kinda mostly a story integrity kind of person, so I don't think that changing it would be so bad.

On the other hand, if it mucks up your inspiration that is of course terrible too. (and honestly, if you took off on a very specific point I think that is totally valid as a story; after all you were working on what you knew at that particular point)

Maybe some tweaking could work? That they aren't afraid of the FBI/jail in general but about this particular FBI/jail because there is some demonic connection or they are on a tight schedule?

Or how about leaving it as it is and finish it for the big bang and then rewrite it the right way after the big bang?