But Guede was always going to say this. It's worth repeating that even though he's been convicted of direct involvement in the murder, Guede still maintains that he was there but had nothing to do with the murder. I think he's in massive denial, coupled with a conscious need to preserve his credibility (as he sees it) by not changing his story.
I therefore don't see Guede's denial of speaking with Alessi, or his re-assertion that Knox and Sollecito were there at the time of the murder, as particularly damaging to the defence per se. And Guede is already a proven multiple liar in relation to this case, so the veracity of his unverifiable testimony can be heavily discounted.
What's of far more interest to me is the inferences that can be drawn from Guede's Skype call with Benedetti, in which he was unsure (to say the least) of Knox's/Sollecito's presence. Strange how his memory of events seemed to improve remarkably around six months later, when he was apparently now certain that Knox and Sollecito were there. Why, in other words, wouldn't Guede have told Benedetti that Sollecito was the "bushy-haired stranger" and that Knox was also there? After all, he knew Knox by sight and a few shared pleasantries by the time of the murder, and he'd have seen Knox's and Sollecito's images all over the media while he was on the run in Germany.