HINDSIGHT is a wonderful thing and no one involved in the hoax call made to the London hospital treating the Duchess of Cambridge for acute morning sickness would have envisaged for a second that it would have such tragic consequences.

Prank calls have been part of the content of radio programmes for years. The best of them have been packaged into CDs and sold as gifts. And look at how much "fun" is had at other people's expense on April 1.

But, as with every joke, it's a question of where to draw the line - and Sydney radio station 2Day FM has a track record of crossing that line.

Even before the terrible news broke today that nurse Jacintha Saldanha had been found dead, the hoax call made by 2Day FM drew a sharp intake of breath from most people I spoke to. 

One or two people thought it was funny to impersonate The Queen and Prince Charles, seeking information about the Duchess's condition and hoping to speak to Kate herself. But there was a general feeling of discomfort: that it was going too far.

After all, it involved a sick person and patient confidentiality. If it had been immediately spotted as a hoax, it wouldn't have been worth the air-time. If it got through the system - as happened at the King Edward VII Hospital - it had the clear potential to land someone in serious trouble.

Hindsight or not, it was an irresponsible thing to do.

Of course, we do not know the personal circumstances of Jacintha Saldanha, or her state of mind before she took the call.

But the strength of the reaction around the world already makes it clear that the Australian DJs behind the prank will never escape the consequences of their poor judgement.

And let's not forget that they had bosses who took the decision to allow the prank to go ahead.