Coming back to the point of "well, what did she expect? Extra marital sex is a crime there. She shouldn't have reported" - it is not that simple.
What you have to understand about cultures like Dubai is the level of hypocrisy that operates there. Any night of the week, you go into a bar and there is pretty open prostitution going on around you. It's tolerated.
It's not actually legal to drink, but it's tolerated (hotels are licensed so tourists can drink, but if you are resident there and want to buy alcohol you need a permit. Even then, it's not legal to drink in public, or to be drunk in public. As a sexist aside, I had to be on my husband's permit.)
It's not legal to have extra marital sex, but it's tolerated (nobody will check if you are married to whoever you are sharing a hotel room or apartment with).
The problem lies not with the application of sharia law, but with the arbitrary standards with which it's applied. You can get filthy drunk, shag whoever you want and chances are nothing will come of it - until it does. You piss off the wrong person, the police take against you for some reason or you otherwise come to the attention of the authorities.
Then any action that you have taken that would otherwise be winked at becomes a problem. It's a problem of "face", of "honour" - the authorities like to appear tolerant only in as far as it functions to make them look reasonable and strong - but that expires pretty quickly if they don't like the cut of your jib. Dubai likes to market itself as tolerant, but it is actually hypocritical.
I'm not surprised at your friends, miffer. The stories I heard from my cleaner and her friends would make your hair curl with the level of arrogance, entitlement and blindness to the realities of other people's lives.