Your information concerning Charlie Wilkes' assessment of Dr. Rinaldi's measurements is of minor interest, but it reminds me of other Stop-Press announcements by pro-Knox proselytizers: in the summer of 2008, as the investigation came to a close and the defence camps had the opportunity to introduce their own allegations and evidence into the case, Charlie kept making noise about how Amanda had been allegedly physically abused in her questioning on the night of 5 November 2007 (Knox supporters hadn't yet puffed up that questioning to 40 or 50 hours).
In the on-line debates we kept telling Charlie that if he had any news concerning such physical abuse, he should urgently contact Amanda's lawyers, so that this extremely important news could be included in the pre-trial and trial procedures. It didn't happen. Amanda's lawyers in fact denied at that point that she had been physically abused (strangely enough, once the trial was underway, and coinciding with a visit to Perugia by her step-father, Amanda made a spontaneous statement in court - probably to her own lawyers' surprise - and referred to such abuse. That acccusation is now being investigated, but probably not in benefit of Amanda's cause.)
In the same way, Judge Michael Heavey wrote Italian Prime Minister Berlusconi, amongst others, about alleged criminal irregularities in the investigation of the murder, yet did not present any documentation concerning these accusations. He later preferred to decline travelling to Italy to attend the trial as a character witness for Amanda, a good decision in my opinion.
So, as regards Charlie's foot measurements, I would urge him to send Amanda's or Raffaele's Italian lawyers any information he has which contradicts Rinaldi's measurements, and if this information is of use to prove their innocence, I'm sure they'll make good use of it.
The fact that Rinaldi's measurements were part of the famous 10 thousand pages (or more?) of pre-trial documentation that was picked apart for months by two separate and heavily populated expensive hot-shot legal teams makes me think that Charlie's observations won't change the footprint measurements.
I personally would prefer that the pro-Knox supporters deal with much more worrisome issues, like the fact that Raffaele's alibi has Amanda leaving his flat for 3 - 4 hours on the night of Meredith's murder, while Amanda's alibi puts her in his flat all night, observing things like fish blood on Raffaele's hands.