Here's something I'd be extremely interested in exploring:
Imagine if there had been no murder in that house that night. Imagine instead if one of the residents (let's say Knox for the sake of argument) had called the police on the morning of the 2nd to say that someone had broken in and stolen 5,000 Euro-worth of high-end laptops and other portable electronic goods. Let's suppose that the girls had contents insurance covering all the "stolen" items. As many people have pointed out, insurance companies employ specialist investigators, who work in conjunction with the police to try to determine if a claim is genuine, or if there's a demonstrable instance of insurance fraud.
My question therefore is this: what would an insurance investigator have concluded from this scene? Would (s)he have advised the insurer to pay up, or would (s)he have reported that the break-in was staged, that this was a case of suspected insurance fraud, and instructed the police to pursue criminal charges? In this instance, I personally suspect that there would have been nowhere near enough evidence of a staging to warrant a refusal to pay an insurance claim (had that been the scenario).
With all this in mind, I wonder if the defence teams have entertained the possibility of employing an insurance investigator (either a freelance currently-active one, or a recently-retired one) to give a specialised professional opinion on whether (s)he would conclude that the break-in had been staged? Just a thought....