"What do you think of the Danish model where employees, err..." a female journalist was asking when O'Brien interrupted.
"Helena Christensen?", he queried, his face deadpan and his timing just enough off to suggest the gag may have been planned in advance.
When the journalist persevered, O'Brien expressed a total lack of interest in the issue, despite the fact that it had been widely discussed in the morning's newspapers in Denmark.
"I haven't really given it much thought," he said, before passing the question to personnel manager Eddie Wilson.
Wilson then argued that as Ryanair staff are employed out of Ireland, Danish norms did not apply.
"Our employees' relationship is with Ireland, so the Danish model, as much as the German model, or the Russian model, just doesn't apply," Wilson argued.
Later in the press conference, David O'Brien did give the question of employment practices a serious answer.
"Cheer up. We come with good news," he reminded the room, before dismissing the trade union struggle against Ryanair as "an ideological crusade."
In the end, he argued, Copenhagen could simply not afford to turn down so many new jobs.
Below is a picture of Helena Christensen at the Tribeca film festival in 2012. (Photo: David Shankbone)