How to the detriment of Knox/Sollicito. The worst that anybody has claimed is that some pictures of Amanda and Meredith at a Chocolate Festival may have been lost.
I didn't sound like they went to much trouble. In any case, why destroy the hard drives containing the Chocolate Festival pictures but keep the one that might possibly provide an alibi?
It seems like a trivial thing to fake, and to fake so badly in a way so easily discovered. Why, given that everybody was pulling together to provide evidence that helped the prosecution and destroy everything that hindered the defence was the contradictory nature of the blood sample allowed to surface?
In any case, I have no idea of how common such errors/anomalies are.