This discussion may contain spoilers!
Of course, we all know that Crane isn't the one who did it, but I think that the discovery of his sexual fantasies is going to be looked upon as a petty attempt of Bigby's to arrest Crane or throw him down the witching well in the next episodes.
The evidence is placed in such an obvious manner that even the most dimwitted fable would assume that Crane couldn't be so reckless and end up suspecting Bigby instead. They're going to point out the ripped dress, the Huff and Puff stubs (Crane apparently doesn't like smoking, so we can assume that he doesn't have a reason to smoke), his reputation of eating people and being generally distrustful.
There's also Crane telling Bigby that it's more likely that Lilly and Faith's deaths were due to someone else trying to get to him due to his violent behaviour if you roughen up Dee, thus we can imply that he knows something that we don't through the Tweedle brothers' findings, something about the motivation behind the killings.