I know nothing about the legal system in Saudi Arabia; however, if there are trials, if there are witnesses, and if the witnesses are required to swear an oath to tell the truth, do you for one minute think that the Saudi authorities would allow a Christian to swear the oath on a Bible? I didn't think so.
Yet, in the United States, where it has been the custom for witnesses to swear an oath to tell the truth on the Bible, some radical Muslims demand the "right" to swear the oath on the Koran.
There is an old saying, which I would recommend to those Muslims--"When in Rome, do as the Romans do."