(First of all, negative karma preventing me from commenting in Sandcastle's post, so I am ranting).
The offshore buoys frequently show "different" conditions than you might see at the beach. The complex shoaling and refraction of the waves around the SF ebb bar can create wave caustics (crossings) that make our spot so famous. For instance a northwest swell will travel straight across the bar in some places, but further to the south it will bend around the bar so it is propagating from the southwest. So the caustic effects and the refraction and shoaling processes can really jack up the surf as compared to measurements at the buoy. This is especially evident with the long period swells. Throw in another 15 s swell from the south and you have some very complex but interesting stuff going on! Take a look at the image from CDIP for Sunday afternoon that shows how the ebb bar causes the waves to be so much bigger than they are offshore.
But yeah...still not convinced it was 10 ft!!