McCullough had not only gone beyond the point Naseem Hamed had set for execution but was giving the champion cause to reflect on the pitfalls of boasting. "I didn't think for one second that Hamed would win as he liked," McCullough said afterwards, "but he'd predicted the third so getting past it gave me a good feeling."
If treated generously in official assessment - one score of 118-110 insulted McCullough's courage and persistence - Hamed was never in danger of losing his World Boxing Organisation title, but it was not a performance to justify the high opinion he holds about himself.
Indeed, Hamed's failure to impose advantages in speed, power and weight (he probably entered the ring a half stone heavier than the Ulsterman) made veteran ringsiders think about what a young Azumah Nelson (the former featherweight champion is still fighting at 40) and other modern stars in the division like Vicente Saldivar, Salvador Sanchez and Alexis Arguello would have done to him.
A growing conclusion about Hamed is that the unorthodoxy from which he has prospered carries the seeds of its own destruction. If his natural explosiveness does not get the job done, there is no reliable method to fall back on.
In answer to criticism of the chances Muhammad Ali took as the young braggart, Cassius Clay, his famed trainer, Angelo Dundee, said that a bad habit is only a bad habit if it does not work.
In Hamed's case bad habits might prove disastrous against the heavier men who are avoided in the policy of his advancement. The true test of Hamed will come against opponents who have not been selected from a lower weight division.
McCullough touched on this when declaring that Hamed was often amateurish in application. "I was a super-bantamweight fighting a featherweight who has knocked a lot of people over," he said, "but he never came close to getting me out of there. Once Hamed realised that he couldn't be rid of me he ran. If I hadn't been prepared to take the fight to him I could have sat in my corner and had a cup of tea."
In mitigation it has to be said that the delay in arrival caused by visa difficulties left Hamed without enough time to acclimatise. There is less substance, however, in the theory that his disorganised boxing can be explained by a six months' absence from the ring.
Hamed may already have peaked and the consequence of an irreparable rift with his mentor, Brendan Ingle, is intense speculation about what the future holds for his association with Frank Warren. Significantly, Hamed's promoter will neither confirm nor deny that their relationship is now fragile. "No comment," Warren said when the question was put to him yesterday.
Plenty happened in Atlantic City, before and during Saturday's contest to disturb executives of the American cable television network, Home Box Office, that has tied Hamed to a multi-fight contract.
The champion's crass behaviour at press conferences was widely reported in American newspapers and seen as a poor advertisement for British boxing. "This kid has done nothing over here to justify the claims he makes for himself," said a leading New York columnist. "Alright, so he had the heart to get up and knock out Kevin Kelly in New York last year but all that posturing in the ring, making faces when he should be going about his work, makes him look ridiculous and is a waste of talent."
The truth about Hamed is that he has learned very little about the fundamentals of boxing and lacks the humility to seek improvement.
Thus McCullough was able to give a much better account of himself than had been generally imagined. He did not have enough to capitalise decisively on Hamed's technical shortcomings but he was never remotely in danger of being separated from his senses.
As for the marked features McCullough brought to a post-fight press conference, he insisted that he had suffered more against lighter men. "In any case I always mark up," he said. "They're unlikely to give me a rematch but I don't feel like I lost this fight. For the first six rounds Hamed kept chattering away, telling me that I can't punch, but he didn't have much to say after that."
Twice during the fight, in the fifth and 10th rounds, McCullough was caught by short left hooks that caused an imbalance in his equilibrium. "I felt those shots," he said, "but my head was clear enough to remember that he doesn't throw clusters of punches. That was one of the things Ken Coombs [his trainer] impressed on me and for once in my life I listened. It didn't ever seem that Hamed wanted to press the fight, that all he wanted to do was hit and run."
In his one public rehearsal last week Hamed looked great, but on the night he gave a very poor performance. Moderating the awe in which he holds himself (from being the greatest of all time he was now merely great in his estimation), Hamed said: "There isn't a featherweight who can beat me."
McCullough had not beaten Hamed - but all the applause was going in his direction.