This was tribal roadkill, not Islamic Sharia law.
Islam very specifically says what punishments are metted out for what crime and it is very specific about the prohibition on sex of all unmarried people.
Most Islamic countries are still quite undeveloped and have lots of tribal groups and traditions still in effect. When things are done according to these tribal traditions it doesn't make it OK with Islam just because it happens in an Islamic country.
Another example is female circumcision. No where in the Koran is that mentioned or advocated. It is completely unheard of in Islamic nations in asia and on the Arabian noodleula. However, in Africa, where it was part of pre-Islamic tribal customs, it remains and some of those groups try to use Islam as a justification for it. The most respected and most scholarly court in the Islamic world is in Egypt where tribal customs perpatrate female circumsision. Egypt made female cicumsision illegal (completely inadequate on eforcing this law though) so the groups that wanted to continue perpatrating this barbarity sued to Egypt's high court to get the law overturned. The Egyptian high court found that there is absolutely no place in Islam that supports mutilating girls and upheld the law. Not exactly the result the tribals had wanted.
NUKE,
Yes, many great scholars were Muslim, a long time ago. If you had been alive in 1000AD you would have wanted to live in a Muslim city like Cordoba or Bagdhad over any other place in the world. The European renaissance was sparked by the marvoules books and ideas brought back to Europe by the Crusaders. Books and ideas taken from the Muslims. Islam was very liberal 1000 years ago, now it is a stagnant morass of conservatism.