It's not just any case is it, SH. The pressure on those officers is immense, and if the press gets a whiff of the parents not actually not being suspects it could be 2007/8 pandemonium again.
I can quite understand the Met not wanting to risk that. It's a case that could ruin careers, as it did in Portugal of course. The London police know that.
(All just my opinions of course, but we all do sometimes forget just how high-profile a case this is I think).
I see your point, Lyall. Pressure is a big factor here. But the way I see it is that that pressure, and the spotlight SY and Cameron are under, actually make it less likely that they would take a risk in investigating the matter according to agendas, rather than according to investigative principles.
The consequences of adjusting their investigations and policies to fit the McCanns (or whomever they are trying to please) could backfire horribly against them. Worth the risk?
And if the investigation would be sacrificed to these agendas, whatever they were, then by definition it would not be being conducted properly - and there would be less chance of getting to the bottom of things. Another thing that does not make sense, taking into account the pressure here for the case to be solved.