None of the above.
Nencini is trying to refute the reality of the break-in, as well as any notion that it would have been Rudy himself who would have staged a break-in. Presumably, the thought that Rudy might have been let in by Meredith, then Rudy killed her, then Rudy as a lone-attacker staged a break-in to divert attention from it being someone "known to have had a date with Meredith" is ludicrous to Nencini.
Nencini is of the opinion that it was Knox who let Rudy in, but that Rudy's presence was otherwise not bothersome initially to Meredith either.
Nencini combines this with his unique notion that Rudy was a professional burglar. No one else views Rudy that way, and most certainly neither Mignini in Perugia nor Crini in Florence entered that notion into evidence - even as one of their famed, "it is probable that's......" Nencini just makes it up.
So, Nencini sees Rudy as a professional, and as one would have had facility to come in through the front door, locked or not locked, and would not have staged a break-in to divert an investigation from a planned encounter with Meredith, because, Nencini says, that style of break-in was known to the Perugians to be Rudy's method.
Are you confused yet?
Nencini, though, defaults to the other strange notion..... that it was Amanda Knox who both staged a break-in in a manner seemingly to point to someone like Rudy, THEN Amanda counter-intuitively named Lumumba at interrogation. This begs the question of why go to all that trouble only to do a double reverse!?
But the short answer to your question is that Nencini just invented all this. No one has ever claimed that the Perugians recognized this as Rudy's method - although given his antics in Milan, perhaps they should have!
