The adjudicator examined the amounts due. He agreed with the main contractor that some work was defective and that the subcontractor was late. He deducted for these, but rejected Northern's request to deduct for the consequences of late completion, as the amber notice was defective. He also refused to deal with the alleged repudiation, saying he had no jurisdiction to deal with something unless it arose under the contract. But he was wrong.
Repudiation does arise under the contract.
So, he had the power to deal with that topic but didn't. He ordered Northern to pay the balance to Nichol. It refused, so Nichol went to court. Barristers for both sides agreed that the adjudicator was wrong about his jurisdiction. Northern argued that the whole decision was therefore null and void.