Right. Time to address the issue of what Sollecito argued in the Supreme Court, regarding the link between him and Knox. It seems that this issue has gone over the heads of many people (including, apparently, "lawyers"), who may just be guilty of viewing this particular issue through a somewhat clouded lens.
Firstly, what Sollecito argued was this: The courts should not use any evidence against Knox as automatic evidence against Sollecito, since the courts should not automatically assume that they acted in concert, nor that they were together all night.
This is a perfectly valid legal assumption. For all Sollecito knew, Knox might have slipped out of his apartment in the middle of the night, murdered Meredith, cleaned herself up, come back to Sollecito's flat, and slid back into bed beside him. He had already judged this as a highly improbable scenario, but he could not be 100% certain. Nor could anybody in his position be certain.
What he was, in effect, arguing is this: "I state that I wasn't there, and was not involved in the murder. And regardless of the fact that I think Amanda was most likely with me all night, I cannot 100% be sure that she was, since I was asleep for part of the night. Therefore, if you (the courts) find evidence placing Amanda at the murder scene, you can't automatically assume that I too was at the murder scene. You must, instead, find independent evidence placing me personally at the murder scene before you have the right to place me in custody."
This interpretation of his argument before the Supreme Court does not in any way imply that Sollecito is now claiming that Knox actually did leave him in the middle of the night to murder Meredith. Rather, it's simply making the very valid legal point that if the courts have incriminating evidence against Knox, then this evidence should not automatically be used against Sollecito. Another way of looking at it is that Sollecito is essentially saying: "If you have very strong evidence pointing to Amanda's involvement in the murder, then I must assume that she has deceived me and that she did indeed slip out of the house while I was sleeping to commit the murder - but I was not involved".
Note that whichever way you look at it, Sollecito's argument is entirely predicated upon the police/prosecutors presenting good evidence of Knox's involvement. At the time these arguments went before the Supreme Court, there was no evidence pointing specifically at Sollecito, other than the incompetently mis-attributed shoeprint. Even the kitchen knife wasn't strong evidence against Sollecito personally. To my mind, Sollecito was perfectly entitled to examine the possibility that Knox had deceived him. But his argument before the Supreme Court does not logically imply that he believes Knox to be guilty of the murder of Meredith Kercher.