Worse, there was no physical evidence of a forced sexual orgy, there was no evidence that Knox or Sollecito were interested in such an orgy, there wasn't even any evidence that they had the slightest inclination toward that kind of behavior.

In other words, it was a hypothesis drawn from nothing, created in order to support a larger hypothesis that was based on extremely weak evidence and made before a far more likely guilty party was known.

The massive amounts of evidence pointing to Guide should have made this possibility extremely unlikely, and without it there was absolutely no reason for Knox and Sollecito to be involved at all.