My understanding (from the way it was reported) was that he had a pre-paid security check, allowing him to pass through the usual gate-checks.
She didn't realise this and took offence when he was waived through from the back of the line, while she was removing her shoes. Thinking she had her 'gotcha' discrimination moment, she started filming, following him, and generally being belligerent.
He was (probably) an entitled arse too, because I have class prejudice, and can't imagine him any other way.