It's somewhat ironic that Knox wanted Guede to tell the court her version of the "truth", but when she lied about Patrick and caused his arrest, she did not come forward at any time and tell the truth. Neither did her mother. They both knew that Patrick was in jail because of lies told by Knox, and they remained silent.
Knox: "The only time that Rudy Guede, Raffaele Sollecito and I were in one room together was in a court room.... He knows what the truth is. I don't know what happened that night," she said."
Knox's mother: "Mellas said Guede "continues to lie about Amanda and that's unfortunate."
CNN
It is indeed unfortunate when two people know that an innocent man is in jail and they choose to remain silent.