It would be interesting to know the diplomatic background of of the trip.
Likely the Saudis were putting a lot of pressure on the State Department; imagine the outrage in the US if the daughter of US Senator was put on trial in Saudi Arabia under the Sharia laws regarding rape and you get some idea of political problems this must be causing the Saudi ruling family.
Perhaps the objective of his visit from the US perspective was to make the point that under US law this was a state matter, and that the US Government could not intervene even if it wished to?
"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." -Manuel II Paleologus