Because Dubai has such a reliance on tourism, it was felt that a "lenient" sentence was called for.
Here's a quote from the story, from another British woman:
"Before I came here I read up on the dos and don'ts. I wouldn't dream of kissing my friend out on the street. This is an Islamic country. We have to respect their traditions. We expect the same in our country. You should dress and behave appropriately when you are somebody's guest."
Now that's interesting.