Well - that's not strictly true. The doctor who performed my abortion many years ago was actually arrested the next day. Imagine getting up in the morning, feeling pretty miserable and seeing that on the front page of the paper. There was a big trial and he and another doctor were charged with breaking the law.
However, it was their case that changed the laws in Western Australia and we now do have much more liberal abortion laws. But it's still not strictly `legal' - only under specific circumstances.
Here's the story. It's a shame this links to a pro-choice forum (I don't do these kinds of forums on either side of the debate but it's the best article from what I googled).
http://www.prochoiceforum.org.uk/al5.asp