You can read that patent here: http://www.google.com/patents/US7812826
And, even thought that patent was _not_ referenced in the case, you will see it's a particular multi-touch behavior _associated with pinch-to-zoom_ that apple is claiming a process invention against, not pinch to zoom. It's actually quite clever.
See: http://www.theverge.com/2012/8/30/3279628/apple-pinch-to-zoo... for good details on this myth.
Note - others have patented Pinch-to-Zoom far before Apple came to the stage.