Well, I've said it before and.....etc
The Italian criminal justice system is not fit for purpose.
It appears that all courts in Italy, up to and including the Supreme Court, are fundamentally not prepared to consider police misconduct. They are prepared to accept that the police may have made mistakes of omission or incompetence in an investigation, but it appears there's an institutional refusal to recognise the possibility of police misconduct.
I suspect that part of this is rooted in general reactionary attitudes among the judiciary (one can examine Justice Lane's extraordinary statement in one of the early appeals of the Birmingham Six in the UK for an example of this - or, much more topically, the long-belated prosecutions of various police on misconduct charges in respect of the investigations into the Hillsborough tragedy). After all, if the public know that senior judges think the police are willing to lie, cheat and employ unlawful means in the course of their investigations, this can have hugely damaging effects upon the faith of the public in the entire law enforcement process. And, in turn, that can lead to significant problems in enforcing law and order.
Fortunately, in the UK (and most other similar countries, I believe), this issue has now been substantially addressed and corrected. It is not now taken as read that the police behave with the utmost integrity at all times (and that therefore a defendant must be able to PROVE misconduct BARD before the court will ever be prepared to accept that it could have happened). Instead, there is a constant implicit onus upon the police to prove that they acted with probity, within the law, and with proper ethical standards. In the UK, the Police and Criminal Evidence Act (PACE) went a very long way to legislating in this direction. As a result, what happened in those interrogation rooms in Perugia on 5th/6th November 2007 almost certainly could/would never have happened in the UK.
I also suspect that in Italy (as well as in other corrupt, second-world nations such as Turkey and Russia), there's something of a prevailing attitude - among legislators, law enforcers and the judiciary alike - along the lines of: "the odds are against us with all these organised crime gangs and corrupt citizens - why not allow the police a decent bit of latitude to fight fire with fire?"
Whatever the underlying reasons are, I maintain that there are extremely strong reasons (supported by a good amount of reliable evidence) that Sollecito (and Knox too, of course) was unlawfully coerced and bullied by the police in that 5th November interrogation into changing his recollection of events into something that the police wanted (NEEDED) him to change it to: that Knox had left his apartment for a lengthy time period on the evening/night of the murder. It's clear that Sollecito was coerced and bullied into convincing himself that the events of the evening/night before the murder (i.e. the evening/night of Halloween, 31st October) were actually the events of the evening/night of the murder (1st November). Everything he told the police in that coerced statement chimes reliably with known events and movements from that Halloween evening/night. Sollecito didn't lie to the police. He was bullied and coerced so assertively that he mixed up the two evenings.
Hopefully the ECHR will see all of this for exactly what it is. I always suspected (and have written about it before) that Sollecito would probably need to end up taking this to the ECHR to get a proper, first-world assessment and adjudication. I trust that Sollecito's lawyers are preparing an ECHR application even as I write (actually, I wouldn't be surprised if they'd already started preparing it in advance of this Italian SC ruling........).