Relaxing in his Cornish farmhouse with his family and two cats around him, it is hard to picture Nicholas Jeffries as a man who less than three months ago was facing the very real prospect of a corporate manslaughter conviction in the Hatfield rail crash trial.
Indeed, Jeffries himself admits that the whole trial is now something of a blur. 'This trial feels like a dream, ' he says.
'You don't feel it's happened. It is so unbelievable.' But back in February and March in the early days of the trial it was all too believable.
'After hearing the prosecution's evidence, I had a period when I was very low. I was put on antidepressants.
'I was so angry. I was not the person I normally am. I am normally cheery, but my temper got very short, ' he says.
'But gradually, thanks to the prosecution's own witnesses, the tide began to turn. Not one witness said anything that harmed us, ' he says. 'Because we were speaking the truth.' Jeffries is still angry that the decision was made to prosecute at all. He believes the Crown Prosecution Service (CPS) started with an objective of corporate manslaughter.
Looking back, this began the day after the trial, he says.
'We were briefed the day after the accident by Balfour Beatty's solicitor. He warned us that we would be interviewed by the police, some of us under caution.
'We were expecting that, but as we didn't feel guilty we told them everything.' In retrospect that was a bad move, says Jeffries. 'I really never believed I was likely to be singled out. Several hundred people were interviewed, some perhaps were more guarded.
I'd be wiser now - what I volunteered is probably what got me into trouble.
'They used our statements against us. The CPS took my statements, six to seven hours of questioning over three interviews and took segments to bring my indictment. The waiting to hear who would be charged was horrendous, ' he says.
'Gradually, over the course of a couple of years, the names of people who weren't going to be prosecuted were released in batches, and of course it didn't come to me. Then came the actual announcement of the prosecution. It came as a hell of bang. I felt numb. Only your belief in your innocence keeps you going, ' he says.
But Jeffries carried on working, albeit now for Amey, having quit London to seek sanctuary in Cornwall. This probably turned out to be the best decision he made.
'During the trial it is what probably kept me going, ' he says. 'I left Balfour Beatty in 2002 and came down here - partly to get away from commuting into London, but really to get back to a hands-on job.
'It was a bit of a career stopper. I have taken a step down to come here. But I have long given up my career for happiness and fulfilment.' Jeffries is now with Network Rail after Amey's maintenance operation was taken back in-house. Both firms have supported him through it all.
'Amey - which took me on despite knowing what was against me - really were supportive. I owe them all a few pints.
'It really is hard to thank everybody. After the verdict I had so many text messages my phone filled up. The support I have had used to bring me to tears - and still does. It is partly what brings you through, ' he says.
The build-up to the trial was fairly routine, he says, although the choice of judge came as a shock - Justice MacKay was the judge who sentenced Great Heck driver Gary Hart to five years.
'The first year was just part of the job. I've attended many inquiries in my time, lots of them where many more people were killed, ' he says. 'Before the trial it was a kind of frozen fear.' When the trial started the real worry set in. 'The opening statements set the tone. That's why I feel so aggrieved at the CPS; on the first day, when all the press were there, they made us sound terrible. Then when we gave answers they had all gone away. That's why you get headlines like 'Bosses walk'.
Jeffries' frustration stemmed from his perception of a lack of desire in the prosecution to recognise that engineering is about making judgements.
'The prosecution's case was that I should have seen the Ventry guidance about gauge corner cracking (see News) and put 20mph speed limits everywhere. My argument was that if I had suggested that people would have thought I had gone mad and would have had me locked up.' In the immediate aftermath of the accident 1,150 speed restrictions were imposed.
'Essentially the prosecution line was we should have slowed the line for three months while Railtrack cured the problem (of gauge corner cracking).
'I maintain that failure was 60% failure to rerail. That decision would have been Railtrack's.
'But regardless of that, always the hardest decision to make is whether to put in a speed restriction. It is something you do when you have to, but at which point do you make that decision when something has been deteriorating for years and years-' he asks.
'Frequently throughout my career I have been faced with track in need of renewal, and the only real way is to put a speed restriction on.
'That removes the risk to you, but you actually increase the risk elsewhere, ' he says.
'Most rail accidents in history have occurred when trains were behaving not normally, operating on different routes or to different timetables.
'Then think of the impact on the roads. If the effect of you delaying a train means you have people jumping into cars, and then driving fast because they are late, it's a factor.
'Perhaps I shouldn't think like that, be egocentric, but I can't.
Essentially civil engineering on the railway is a matter of judgement. There are a lot of things that add up, and while you can write rules, they can only ever be guidelines really.
'The easiest thing to do is to put on speed restrictions. But it is not your job just to cover your backside. And that's why I am here today.
'During my time as a railway engineer tens of millions of people under my care have got safely to their destinations. If I was a twit, in my 39 years many more wouldn't have.' Getting the court to recognise this fact wore Jeffries down, and that had an impact on his family.
'I didn't quite realise how upset the kids were. At the start the press were terrifying.
'Linda (his wife) suffered many more times than I have.
She wasn't in the front line, and wasn't directly involved with the full facts. But it was especially worrying for the kids. I was so busy worrying about myself, I didn't realise how much other people cared and worried.
'At least I knew I was going to have my chance, ' he says.
Jeffries was the only defendant to give evidence - despite much advice from his own counsel and others to the contrary.
'There was a thought that by giving evidence I was sticking my head above the parapet, he says.
'But I thought so many lies had been told about me, ' he says.
'The dismissal of the manslaughter charge I took fairly neutrally. Manslaughter - they could have put me in jail. I was thinking 'how do I get my kids through uni then-' Yet I met the news with no elation.' But the jury verdict was very different. Jeffries broke down in tears shortly after hearing the words 'Jeffries, Nicholas. Not guilty.' 'I can't describe what I was like as the foreman of the jury announced the verdicts. 'I was last. It seemed like hours, yet was only a matter of seconds.
'Even then I stood there calmly. I was still quite composed. It was only when the judge left the room that I broke down. I never thought I'd feel such emotion. I never will again.'