Sheikh Issa, who is the half brother of UAE President Sheikh Khalifa bin Zayed al-Nahyan, has been cleared of all charges of torture, but the judge presiding over the case has failed to give an explanation for the verdict.
It was the first time that a member of the nation's ruling family had been put on trial and the outcome has been questioned by several international observers.
Ibrahim al-Abed, General Director of the Emirates News Agency, say the ruling is final.
"The court has decided and that is all," he said. "Some people have started questioning the decision… It's too late because when the court makes a decision nobody has a right to question [it]."
Sheikh Issa's actions came to light last year when the US television network ABC aired footage of him apparently torturing Afghani grain trader Mohammed Shahpoor, who is said to have cheated him in a business transaction.
The man managed to survive the ordeal.
Issa's lawyers never denied it was their client in the video, but they say he was drugged by two former business associates beforehand and was not aware of what he was doing.
Lebanese-American brothers Bassam and Ghassan Nabulsi, who publicized the footage, are accused of giving drugs to the sheikh in order to blackmail him.
They deny the charges, but have been sentenced in absentia to five years in prison and fined nearly $3,000.
Sheikh Issa's lawyer, Habib al-Mulla, says the verdict represents the UAE's commitment to the rule of law.
Critics, however, say the ruling highlights the UAE's disrespect for human rights.
Before the judgment was handed down, Democratic Congressman James McGovern affirmed that the Arab nation's track record on human rights concerned him.
"I think anybody who saw the tape that I saw where a member of the royal family was torturing this man from Afghanistan - I think it gives you pause," McGovern said. "At the end of the day, my hope is that the UAE will get its act together and punish people no matter what their stature is if they commit crimes. I do believe that's something the United States should be urging."
The United States has not made an official comment on Sheikh Issa's trial, but McGovern says America is committed to promoting human rights in the Emirates.
"We're going to continue to expose human rights abuses in the UAE and hopefully it will result in some positive developments in the UAE where people who commit crimes, who are high up in the royal family or in the government, will be held to account," he said.
A security guard who was seen on video helping Sheikh Issa carry out his assault has also been acquitted, but a Syrian national has been given one year in jail for beating Shahpoor and an Indian and a Palestinian have both been sentenced to three years for sodomizing him with a stick.
The judge says the reasoning behind the verdicts will be published at a later date.