Thanks Dan O.
The hypothesis that the lie about a "call before anything had happened" was planted as early as 10 Nov 2007 fits the picture and is coherent with what Machiavelli wrote about ILE tactics of deceit.
I have another question. From the trial transcript it occurred to me that the defense lawyers strengthen some other possible paths of attack ( related to the Nov 10 bugged conversation, the Dec 17 interrogation etc. ) by asking preemptive questions. But it is not so regarding that forgotten phone call. It appears that they were unprepared for such an attack and they hadn't rehearsed it with Amanda.
Do you think it was an undisclosed ace in the sleeve of the prosecution, or were there some clear indications earlier that they will attack in this direction?
IMO its not that they where not prepared. Its more along the lines, that if they interceded at that particular point they could do more damage. As an example. The defense knew the exact time. The prosecution knew the exact time. However, the judge and prosecution was using noon or 1200 or 3am in seattle as their times for this line of questioning. If the defense objects and asks them to be more specific about the time. Knox might still answer she dont remember the call because at this point she is confused. So long as they are using the wrong time if it comes up during the appeal process they can just throw those questions in with their many objections about the prosecutions evidence and questioning.