Where's the law?

Here's a funny one - a paramedic has appeared in court, been found guilty and been given a suspended sentence for ignoring a man who collapsed near him on the pavement outside the A & E department of a hospital and who subsequently died of a heart attack. Now let's be clear - this was a morally despicable thing to do, particularly for a trained paramedic. But how was it illegal?  Unlike some other countries' legal systems, there is not (as far as I am aware) any legal requirement for anybody to do anything to help a stranger who is in trouble. And I can't see why being a paramedic changes things.  Of course he may be (almost certainly will be) subject to disciplinary action by his employers, but that's a separate matter. Anybody know any different?