Kean was known for being an expert doctor on rare diseases, but also got embroiled in controversy. Over the years of working with many people he befriended Tim Garrity who was a major gambler and had ties to organized crime. Kean also became a heavy gambler, and after his bookies operation was raided in 1959, he appeared in many newspapers and had to go to court which led to the end of his gambling. He also was caught in controversy after he was alleged to have played a central role in convincing the United States to allow the deposed Shah of Iran to be admitted into the US for medical treatment. President Carter's decision to allow the Shah entry to the U.S. led to the attack on the embassy in Tehran, Iran, in which 50 hostages were taken by militant Muslims and nationalists. However, Kean denied any such role, to the point of suing the journal "Science" for libel. In a settlement, "Science" stated that he had acted both professionally and ethically.