Why does one of the nation’s top journalists quit at the height of his game? Along with plenty of others, I was shocked to read in The Australian yesterday that Hedley Thomas, deserving winner of last year’s Gold Walkley and the man behind the Haneef story, the Jayant Patel story and many others, was leaving the profession to go and work for a resources company.

Why? The answers, gleaned from an interview with Thomas yesterday afternoon, give pause for thought about the stamina it takes and the personal cost of covering big stories for so long – even leaving aside attacks like that mounted by Police Commissioner Mick Keelty the other day (and, to be clear, Thomas’s decision was made long before that spray).

Thomas is getting out for his own sake and that of his family. He has young children, and the stress is showing. He has given more than most of us to the profession, and suffered more than many of us for it.

At a personal level, nobody should begrudge him his new direction, or do anything other than wish him well. And yet as a journalist and a citizen I am dismayed. Too many good journalists leave the mainstream in mid career. Thomas is just 41 years old. How can we keep people like him at the job, happy and healthy, for longer?

Thomas told me yesterday that throughout 2007, even as he pursued the Haneef story, he knew he was burning out: “I was questioning whether I could maintain this enthusiasm and stamina.”

Thomas says:

I am not menopausal, but whatever the male equivalent is, well that’s it. There comes a time when you don’t want to deal with other people’s problems anymore. I get dozens of calls from people who want me to investigate something, rip offs and lawyers and so on, and I used to welcome those calls and opportunities. I am just concerned that I can’t relish it for another ten years, and I don’t want to impose on the profession and my employer by resting on my laurels..

Then someone made a good offer. The Queensland Gas Company in which Thomas has been a shareholder for some time, offered him a communications job in its executive management team. It was his chance to try something new. News Limited head John Hartigan and Australian editor Chris Mitchell tried to change his mind, without success.

There was, he admits, another factor.

In October 2002, when he was working for the Courier Mail, Hedley Thomas and his family suffered a drive-by shooting at their home in western Brisbane. While nobody was ever charged, it was clear that it was retaliation for his work. Four bullets tore into the house, within inches of him, his wife and his children.

Thomas detailed some of the devastating impact of that shooting in his book on the Dr Patel scandal. The relevant bits can be read here.

He considered quitting journalism then “growing vegetables… or taking up a safe PR job”. Journalism had hurt his family, he wrote, and he would never have the same zest for it again. Yesterday Thomas said that incident may still be playing a role in his decision to leave.

Why now? “No-one can accuse me of running away now.”

What about the “high public purpose” of journalism, I asked. Yes, he will miss that. He will miss almost every aspect of the job. And yet he is leaving.

So what might have been done to keep Thomas in journalism? And all those others – we know the names – who show the pressure of the job either by leaving or by betraying themselves with increasingly erratic behaviour.

Perhaps we need to have structured sabbaticals for journalists who have been under such pressures. Perhaps they could take a turn attached to universities, boosting the real-world credentials of our journalism courses.

Certainly managements should free them from that curse of the industry, the pressure imposed by old-fart-kicked-upstairs management types who say “you are only as good as your last story”, knowing that it is a standard that no longer applies to them. We should not drive people who are already too ready to drive themselves.

Having said that, Thomas has nothing but praise for News Limited. He says he has felt well supported by them both through the aftermath of the shooting and more recently. He is confident The Australian will maintain its position and its fervour on the Haneef story.

Perhaps Thomas was one we had to lose. And we should wish him well. Nevertheless, we are the poorer for him leaving.