When you come to choose a potential adjudicator for your contract it is a good idea to pick one of the many nominating bodies. Pick the wrong person and they could be accused of bias.
Are you biased? I have not the slightest doubt that Lord Hoffmann in the Pinochet trial was not. And, when the judgment of the second set of Law Lords is published shortly, I am absolutely certain that they will say he was not.

So why set the Pinochet judgment aside and start again? For all the same reasons that the construction industry in Great Britain and Northern Ireland has adopted and welcomed new adjudication. The person whose job requires him to act impartially has to be seen to be free from bias.

But do take this crucial remark on board: you will never pass the test for bias if you have an interest in the outcome of a controversy. That is why today's job architect or engineer or surveyor no longer "holds the ring" on a building site; that is why the modern architect and engineer has a hell of a job appearing evenhanded when it comes to issuing certificates or extensions of time or settling quarrels.

Like Lord Hoffmann, the modern architect is not biased in fact but biased in law. And lo and behold, the very man who explained all this beautifully – in a case in 1998 called Beaufort House vs Gilbert Ash (NI) Ltd, was Lord Hoffmann himself. "The architect is the agent of the employer. He is a professional man but can hardly be called independent. One would not readily assume that the contractor would submit himself to be bound by his decisions … It must be said that there are instances in the 19th century, and the early part of this one, in which contracts were construed as doing precisely this.

"There are also contracts which provided that in case of a dispute, the architect was to be the arbitrator. But the notion of what amounted to a conflict of interest was not as well understood as it is now." Key words used so far include "bias", "conflict of interest", "evenhanded", and "impartiality". And here are some more: "neutrality", "objectivity", "disinterested", "fair" and "just".

A person may be as straight as a die, as impartial as Caesar’s wife, ”all things to all men” – but not impartial in law

Now draw breath and ask yourself what you are up to when you choose the adjudicator in the contract. Most people enter the name of an Adjudicator Nominating Body. That body will choose the adjudicator. Some are collecting a pile of names and putting them in the contract. Others are playing with fire. They are entering the name of one person. And indeed, that one person may be as straight as a die, as impartial as Caesar's wife, "all things to all men" – but not impartial in law.

So what is this test in law? First obtain all the details about the adjudicator and his relationships with the parties or problem, then ask whether, through the eyes of a reasonable man, there was a real danger of bias in the sense that he might unfairly regard with favour, or disfavour, the case of a party to the issue under consideration by him. The crucial word of that test is "might". There need only be a possibility of bias, not a probability.

So the test in law does not have to prove actual bias. All it needs is something called apparent bias. And, what is also interesting in the Pinochet case is that the attack on apparent bias was made after the decision, even though it is said everyone knew of the Lord Hoffmann's connection with Amnesty International beforehand. So, if you popped a pal's name into the contract as the adjudicator and he was an employee, or a consultant engaged by your outfit from time to time, you are playing with fire. Watch out for the fire man. He is likely to set the decision of the adjudicator aside.

But, finally, what would happen to the adjudicator who knew that he or his company had a pecuniary interest in the outcome? The Construction Act gives immunity to the adjudicator unless he is acting in bad faith. So, if your boss has asked you to be the adjudicator under a main contract or subcontract, and if that is an act of bad faith, could you be sued in person? Answers on a postcard please.