It doesn't mean that the newspaper is mistaken, it means that Sollecito lied about a phone call and that there were inconsistencies in his story regarding the night of the murder. It appears that the newspaper is not going to forget the facts too quickly.
Let's look at the statement:
"Raffaele's statement to prosecutors that he had spoken to his father the night Kercher was killed raised suspicion, as phone records showed no trace of the call."
Phone records showed no trace of the call. It doesn't say that Sollecito didn't call his father that particular night, it says that there was no trace of the call that Sollecito alluded to.
This statement reminds people that there were inconsistencies in Sollecito's statement as well:
"... inconsistencies in his statements about spending the night of the murder watching a video, cooking and making love with Knox in his apartment"
Seriously otto, normally I get your point, but I don't get it at all here. Sollecito did call his father that night, and phone records in fact proved it. All you are showing us here is that the newspaper is doing a bad job by doing a rush job and reporting on things they had no business reporting on (until the clear evidence was known).