I have referred to the slip rule in adjudication on a number of occasions, most recently following Ramsey J’s judgment in O’Donnell Developments v Build Ability. It is a handy implied term for those occasions when adjudicators make a mistake.
Akenhead J’s judgment in Redwing v Wishart provides yet another example of an adjudicator getting his maths wrong and then fixing the problem using the slip rule. (I looked at the reasons point last week.)
In Redwing, Akenhead J described the mistake as a “very obvious arithmetical error”. Instead of comparing like for like (actual prime cost with estimated prime cost), the adjudicator compared apples with pears (actual prime cost with the estimated prime cost plus the weekly contract fee). This meant that the percentage increase from estimated to actual was lower than is should be, resulting in a lower adjustment to the contract fee and less money due to the contractor.
Once the adjudicator fixed his maths, the percentage increase went from 11% to 28%. Perhaps frustrating for the party having to pay more on account of the correction, but given the time constraints associated with the adjudication process, it is not surprising that mistakes and slips do occur. Ultimately, the contractor will get the money the adjudicator intended it to receive, thanks to the court.
While using the slip rule should be an act of last resort for the adjudicator, it is reassuring to know that there is a last resort. It may one day be a right that is on the statute books but, for the time being, I’m happy enough with it being an implied term.
