Interestingly enough, DV's book hinges on the narrative that the police got it very badly wrong in this case and therefore this is his impetus for starting his own investigation. I think, however, that the POW theory is not a new one.
A few things jump out at me here.
First, DV would be aware of what you say in your quote above, so that makes his reasoning for his investigation rather interesting to me (as a kind of side psychological question...hey, he wrote a book, people get to discuss why he did it). At one point towards the beginning of the book, DV meets some of his ex colleagues in the pub and one is from the Murder Review Group. He is annoyed that his colleague told the MRG guy which case he was working on, because he thinks the Met will somehow interfere, warn him off. He is distrustful. He chooses what he says or doesn't say in his book, so why say this? I think it shows that he is distrustful, wants the reader to know he is, because the premise for his book is that the police are barking up the wrong tree--and deliberately so--with the JC line.
If DV knew that the POW line of enquiry would have been investigated, and ruled out i.e. no further action, why does he then follow it, to the point of all but naming a live person? He did get a meeting with the Met to put it to them, they didn't tell him to just get lost, they sat down with him, even though he thinks his theory has been dismissed.
Lots of interesting material here. Thanks
@Konstantin
I consider that DV's relationship with the Met, on account of him leaving with 20 of an usual 30 years service, is the driving factor in him taking on the venture into the SJL's disappearance. As far as we know he hasn't worked on the case as a detective.
DV may have some bad blood with the Met, for whatever reason.
DV needs to earn a living using the skills he has and that he gets a lot of satisfaction from....criminal investigation.
Of all the high profile emotive UK cases to choose, SJL is probably the accessible. Others would be Claudia Lawrence, the Birmingham pub bombings, David Kelly affair, establishment paedophile rings, the Daniel Morgan murder etc. They include reported elements of perverting the course of justice, institutional cover up or serious corruption.
However, they come with great difficulty in finding people to talk and the potential for the men in grey suits and other less friendly individuals to take an interest in what is being investigated.
So I think DV has been quite clever in selecting the SLJ case and to use the focus of the PoW to build his book around. Note I say he choose the PoW, not that there is any credible evidence that pointed him there.....tail wagging the dog.
DV will be clearly aware that the police satisfied the line of enquiry at the PoW and that they do not have any evidential basis to apply for a search warrant. This way his assertion will never be proven wrong. He has been very careful not to name suspects and to explain why he hasn't been able to search but 'may' try crowd funding and to obtain permission from the current PoW owners.
Lots of if's and but's, and all the time the Met cannot comment on the investigation as it is still live.....DV knows this and is playing the system, making money and becoming a unreachable itch for the Met. Result!
But I still don't buy it.....call it plain old boring common sense!