What would be extremely interesting to read would be something as clearly written, objective and well reasoned as Horrocks' theory is (IMO) putting forward a detailed theory of parental involvement. In ten years I have never read a remotely plausible account of this, and I say this not to goad or inflame but simply to state my opinion. In all honesty, has anyone else? Because if you have I'd genuinely appreciate a link to it.
Horrocks says;
The thought that Kate and Gerry McCann had anything to do with the death of their daughter, whether being directly responsible, or covering up an accident, is as far as I am concerned frankly preposterous. Although many believe this, as far as I am aware, there is not one shred of credible evidence, either direct or otherwise to indicate that this is even a remote possibility.
There may be no evidence but there was opportunity and they were the last people to see her. There are many reasons for saying this. Firstly, and importantly, there is no family history that would point in any way to this. I also do not believe that anyone with any sense believes that they killed Madeleine deliberately, so this leaves a tragic accident. Even if such an accident had happened, is it feasible that they would not immediately seek assistance and call for an ambulance?
Is there family history in all such cases? If not, that's irrelevant. There could be reasons why calling for assistance wasn't an option. Are we saying that they coldly decided that Madeleine was dead and then put together an elaborate plan to dispose of her body? Did Gerry McCann simply walk down the road with his daughter’s body and dispose of it, and then calmly go out for dinner. This is ridiculous in the extreme. Also, have they then maintained this pretence for so long, the simple answer is no. And as for it being a conspiracy between themselves and any or all of their group of friends, this stretches credibility beyond belief.
Why would the decision have to be made coldly? Can people put on an act? It depends on the person. Can they keep up the act for years? It would depend on the stakes. The farcical conspiracy theory that the last photo of Madeleine was photo shopped, the spurious and often inaccurately reported forensic findings, the irrelevant behaviour of the cadaver dogs, Mr and Mrs McCann’s perceived demeanour, as well as many other totally immaterial points, just fuel this uninformed and often offensive conjecture. The simple answer is, there is no information, let alone evidence to indicate their involvement in any way. Should they have supervised their children more closely that night; that is not for me to say, but regardless of the answer, it does not assist the investigation in any way.
Why does he dismiss all the above points? Suspicions are formed from lots of indications sometimes and the behaviour and attitudes of people should be noted, not ignored. This person is determined to discredit the idea that the McCanns were involved. He has no evidence which excludes them, just his belief that they wouldn't do that. Hence his use of unnecessary words such as 'preposterous' 'coldly' and 'ridiculous', which are clearly used to persuade. Using emotive language means his case is weak imo.