Dubai Police doesn't seem to be like this. As my colleagues also went to police station and they treated them very well. They offer them soft drinks and food in the evening. After a light verbal investigation, they were released. I also visited the Police Station in Dubai 2 times and found them very soft and friendly while they treat even the foreigners. As AK said, there should be some other story behind that. Dubai Police is the most civilized police in the Gulf.