He's drove into 4 walls this season, The first accident was not at all his fault, he had a wheel failure of some kind. The second was Germany, where he simply lit up the back wheels in tricky conditions. The third was only a brush, but nevertheless he still hit it, It was in SPA in even trickier conditions. The last was this weekend, where if you were listening to the commentary Ant Davidson seemed to think it was caused by the car bottoming out. Although it could have been avoided by not pushing as hard.
So really it's only Germany and Japan that were caused by major driver error.