The way the article, or the author Robert Hardman portrays it, it's like the queen thinks Andrew is "troubled" in some way so keeps him closer than the other children of hers.
".. 'He was not as bright as the others, he could be boorish and everyone knew that,' Hardman said of Andrew.
'David Cameron said to me when I was writing the book, all the other members of the family knew the boundaries, they knew what they were supposed to do and what they shouldn't.
'I saw with my own eyes at places like the World Economic Forum in Davos how Andrew would come in and upset people, say the wrong thing, cross a line...."
They're not trying to lay the groundwork for some sort of spurious mental health / spectrum claim to explain away his behaviour are they?