The former RUC chief constable, Sir John Hermon, said it was "absolutely essential" to establish an independent mechanism for deciding which marches went ahead, rather than leaving it to the RUC.
Asked on a British TV programme on Saturday about Sir Hugh Annesley's decision to let the march go through, he said:
"I think the ultimate consequence of the original decision was such that they had no alternative but to take the action of reversing that decision."
He described Portadown as "the Vatican of Orangeism".
"The ban on their right to march, not least in that area, was total, but so deep were their feelings and are their feelings that they would believe that if that was lost, they would lose everything".
He said that he had faced a similar situation in 1986 and had allowed an Orange march to proceed. The Taoiseach of the day had congratulated the RUC for the way it handled it.