You may be aware of the extraordinary case of CWS vs ICL, and if so, you probably have one overriding question: what on earth was going on in the judge's mind?
Went to the cinema last night. Smelly. It was the popcorn. And have you seen the size of the Coca-Cola carton? It would make a great water-butt. My cinema-going neighbours grazed their way through the movie. It was called Charlie. Do you remember the Richardson gang? This was a film about their trial.

The judge opens the trial by telling the jury that the Richardsons are notorious London gangsters. Dear, oh dear; I bet he didn't. Then the judge is shown putting a fitted-up story in the mouths of prosecution witnesses – witnesses with form as long as your arm. Dear, oh dear; I bet he didn't. The barristers are shown in action, meandering around the Old Bailey, leaning on the jury box, leaning on the witness box, imitating the American style popularised by Perry Mason. Yes, yes, I know it was all done for effect. The villain was the judge. The film was rubbish. I walked out eventually. The smelly popcorn got to me.

Getting to be an English judge isn't easy. Those who do the choosing do it ever so slowly and those chosen are ever so good. They are still human, though, and humans make mistakes. The safety net is the next tier of judges. They watch for mistakes, watch especially for unfairness.

The same goes with arbitrators and adjudicators. The unfairness can be inadvertent; it can "just happen". That fate befell a well-known and well-liked judge in a trial recently. Jonathan Rich told you about him a few weeks ago (13 February, page 48), and he included a lot of what the Court of Appeal had to say. What happened was that the judge became unfair and didn't even spot it.

There was nothing remarkable about the trial. True, the £12m stake was big. True, it took a 20-day hearing. It was, though, just a commercial dispute with lots of noughts on the numbers. The beautiful lesson is what happened to the judge.

The judge displayed no hostility towards either party. It was only when the judgment was handed down that his thinking was revealed

You might not know, if you haven't been in a trial, that the event takes on a life of its own. Things happen in court, and they colour the story. Circumstances begin to emerge, and they add flavour. The original quarrel becomes viewed in different contexts. The shades of grey in the pre-trial papers become vivid reds and greens. The judge, arbitrator, tribunal begins to form views about people, events, behaviour. Answers begin to bleed through that grey canvas. Something inside shouts "this witness is a bloody liar". Or sometimes, something inside murmurs "I don't like this witness". It's human.

This time, the judge here decided that the key people in the claimant's case had acted in bad faith. They were hell-bent on deliberately causing harm to the other party. They "were looking for trouble" so as to extricate themselves from the project and to find an opportunity to "exact revenge". But wait a minute … the target of all this bad faith didn't make that complaint. It was not even suggested by them. Nor was it made a complaint by amendment during the trial.

Actually, neither party realised these impressions were forming in the judge's mind. He conducted the trial perfectly. He asked virtually no questions. He allowed both parties to develop their cases as they liked. He displayed no hostility towards either party. It was only when the 200-page judgment was handed down that the judge's thinking was revealed. He had formed the view that the claimant had acted in bad faith. Their £12m claim failed in its entirety and they suffered a comprehensive defeat.

Do you see what has happened? The judge had formed a view that the complainant's management was dishonest. The Court of Appeal said that that finding was obviously unfair. The party considered to have acted in bad faith had no opportunity to rebut the claim. The judge ought, in fairness, to have put his concerns to the parties. He simply had not heard what the party most affected had to say about what concerned them. The entire case is to go for retrial.