I don't know how Lancashire police come to the conclusion so early on that falling in the river was the main theory. It is one theory. But they deliberately said there was no way in and out of that area that wouldn't have been picked up by cctv cameras.
Now we know that the route Nicola takes regularly, in and out, isn't covered by cctv. So if Nicola as just walked off the chances are she'd go back out that way. Or if someone as taken her after falling her he would have come in and out that way too.
They have totally messed this investigation up. Then the icing on the cake was they released her private information, which at this stage didn't add anything to the investigation. If she is alive and can see that private information about her, its not going to encourage her to come back.