I'm glad the outcome was so mild for a head on crash. It could have been much worse. Good on the insurance company for making everything right. It sounds like both riders reacted the best they could with the unexpected conditions. Things happen, but I would have felt horrible if I had been the at fault rider. It was kind of the OP to be nice to the guy, and that will likely come back around some day.
Like someone else said, however, a patch of sand does not equal negligence. With the debt our government is currently building, we can't even afford to pave roads, much less sweep them. If you sue the state, you are suing all of us who pay taxes. The assurance of clean pavement can only be expected on a race track.