To a Koran believer, Islam is never supposed to be driven backwards. So seeing that happen either means giving up Islam or denying they saw what they saw.
It is my understanding that they believe the Koran was written by God, and that what they possess is merely a copy of the Holy Book which is kept in Heaven. It is unchanging and perfect in their eyes. I am told this is a tenet of Muslim faith.
What sort of consternation do you suppose it would cause, if the wider Islamic world were to be made aware that there exists earlier copies of the book which do not Jive with their current version? :)