Journalists spend most of their working days in familiar environments. For me, that mainly means the Sky News studio in London, following a well-worn routine: interviews, breaking news, discussions.

But our job also requires that we confront the unfamiliar and, occasionally, the unsafe. In my greener days that meant Afghanistan, Iraq, Lebanon, Libya and many other places besides.

Now those forays into warzones are rare. One reason for that is my family circumstances. I have a large family, five young daughters and a son.

They have changed the tempo at which I work. Fewer breathless dashes to the airport, more school runs. They have also changed the way I do my job. Good journalism takes many things and the empathy I hope they have wrought in me is one of them. But so is understanding the boundaries of decency and taste. And from time to time, we screw up.

At the weekend I got things wrong. If there was someone to apologise to in person, I would. While presenting Sky's lunchtime coverage of the flight MH17 disaster, I stooped down to look at a piece of debris. It was a child's suitcase. I put my hand inside and lifted up a water bottle and a set of keys. As I did so my mental circuit-breaker finally engaged and I apologised instantly on-air for what I was doing.

Within minutes there was outrage on Twitter. Within hours the story had gone viral. I was accused of rummaging through personal belongings, contaminating a crime scene, desecrating a sacred site.

Certainly it was a serious error of judgment. I acknowledged that and so did Sky. My bosses issued an apology by tea-time. They were supportive and keen to stress that they understood the context of the gaffe.

And what was that context? What can mitigate the seemingly indefensible? I doubt many of my more roar-throated detractors on Twitter feel there can be any justification for such morally insolvent behaviour.

But, as we move into a world where excoriation comes quickly and explanations come slowly, I would like to offer another view.

The crash site of flight MH17 is like the set of a horror story. Except that movies are never allowed to show what we saw over the weekend. As I type I can smell the nauseating scent of death that clings to me still. I have seen burned bodies before – I was a 17-year-old football fan caught up in the Bradford football stadium fire – but nothing on this scale.

I have covered aviation disaster stories before too. In 2002, I reported from Lake Constance after a DHL cargo plane collided with a jet carrying a school party from Bashkortostan. Within hours police had sealed-off a sterile area and no journalists were allowed in, while forensic investigators and recovery teams went in.

The Ukraine situation could not be more different. There are no police to unspool tape and cordon-off sensitive areas. There are roadblocks manned by sullen-looking teenagers cradling AK-47s, but no meaningful law and order. It is a warzone and the men in charge carry guns and grudges.

So I, and many others, were allowed to walk around the crash site at will.

The sights were shocking. I could not comprehend what we seeing. Bodies and body parts everywhere. I phoned my wife. "It's a butcher's yard", I said.

Colin Brazier in the Sky News studio Photograph: Justin Downing/Sky News

We began broadcasting. Not short reports, but long, thorough background pieces. Interviews with our correspondents in Moscow and elsewhere. Sky has pioneered this type of open-ended presentational outside broadcast. It is a journalistic high-wire act, but one which consistently delivers insights that anchoring from London cannot.

There is no studio and, at the crash site, no obvious frame of reference. We took an instant and simple decision to avoid pointing a live camera anywhere a corpse might be seen.

What about intimate belongings? They brought home the poignancy of the tragedy. They told a story of lives – swimming trunks, laptops, duty free, books – snuffed out in an instant.They provided the backdrop for me to ask why victims were being left to rot in the sun. Other journalists, some well known broadcasters, were handling belongings and speaking to camera. In a place without rules, I foolishly took that as a precedent.

And so during that lunchtime broadcast I stood above a pile of belongings, pointing to items strewn across the ground. Out of the corner of my eye I spotted a pink drinking flask. It looked familiar. My six-year-old daughter, Kitty, has one just like it.

I bent down and, what my Twitter critics cannot hear - because of the sound quality of internet replays of the broadcast - is that I had lost it. It is a cardinal sin of broadcasting, in my book anyway, to start blubbing on-air. I fought for some self-control, not thinking all that clearly as I did so.

Too late, I realised that I was crossing a line. I thought aloud: "we shouldn't be doing this … this is a mistake", an instant apology that was only selectively quoted by those determined to see what I did as a powerful example of journalistic vulturism.

• This article was amended on 24 July 2014. An earlier version said a plane carrying a school party from Kazakhstan had crashed at Lake Constance in 2004. The date was 2002 and the school party was from Bashkortostan.