The 24-year-old former American Football hero of the University of Oregon, who missed a medal at the Olympics by one place last summer, ran 12.84sec last month, beating the team-mate who retained his world title last night, Grant Holloway, and putting himself third on the all-time list.

That is to say, he really could have won last night.

Later this year Allen will sign a three-year contract with National Football League's (NFL) Philadelphia Eagles, although he says he plans to combine this sporting career with track and field.

I spoke to him last month for the first time, at a press conference on the eve of the Diamond League meeting in Paris, and he was smart, interesting and funny. All this combines to the point where calling Allen a local hero resonates with truth.

Bitterly, his ambition was thwarted by a thousandth of a second - the margin by which he infringed the World Athletics rule relating to false starts, which states that an athlete's reaction time, recorded electronically via the plates of his or her starting blocks, cannot be quicker than a tenth - 0.1 - of a second.

Allen triggered that timing at 0.099sec. It was hardly a flyer.

"When I was flagged I was very surprised," Allen, who not surprisingly questioned the decision, told reporters afterwards. "Which, you know, was also part of the frustration because I know for a fact that I didn’t react until I heard the gun.

"And to be one one-thousandth too quick... it kinda sucks."

For every reason, it was not hard to understand why Allen was desperate to get the best of getaways.

As he waited in his blocks in the final alongside the leggy Holloway - also a huge American Football talent who memorably responded to being asked why he had given up the game by saying: "Because I still want to be able to walk when I’m 30" - he was next to the athlete he regarded as a wonder starter.

Speaking before he ran in Paris, a jocular Allen commented: "If I had Grant's start I probably would have run 12.6 by now. But he’s the greatest in the history of the 60m hurdles and probably the greatest starter for a long time.

"Me and Grant have spoken about that. I said, 'Hey, teach me how to start', and he said, 'Teach me how to do your last four!'"

It was one of the favourite sayings of British sprinter Linford Christie, who won the 1992 Olympic and 1993 world 100m titles - "Go on the B of Bang!"

Under huge pressure at the Atlanta 1996 Olympics from brash Canadian Donovan Bailey, who had taken his world 100m title the year before, and needing to get away like never before, Christie went just before the B - not once, but twice - and was momentously disqualified.

It's fair to say he didn’t react too well, stalking down the straight and pulling down the top of his running vest, while offering any hapless official who came into his path a death stare.

But the figures were there.

"The first one I knew I did, but on the second one I felt I reacted perfectly to the gun," Christie said. "I have never been disqualified from a race before in my life. What a place to do it."

His reaction time was 0.086sec.

At that time athletes could have the benefit of one false start, being disqualified for a second. In 2003 the rules were changed - somewhat illogically - so that one false start in any race was permitted, but thereafter there was no mercy for anyone.

Commenting on that change, Britain’s then-European indoor 60m champion Jason Gardener said he believed the ruling would "eliminate multiple starts in races", adding: "With the old rule it's been very annoying, especially in championships, where you could be in a semi-final and there could be six false starts… all athletes will have to become more disciplined."

Others opined that the change came to maintain the sanity of TV producers.

Later that year, at the World Athletics Championships in Paris, I was among those who witnessed one of the highest-profile protests against a false start ruling as Jon Drummond of the United States, disqualified along with Asafa Powell of Jamaica from his 100m quarter-final, staged a one-man protest that delayed the race by an hour, maintaining he had "not moved".

Unwisely perhaps, the organisers replayed the start on the big screen, where it was far from obvious that Drummond had gone early. The crowd began to boo, as they did in Eugene.

Drummond began by lying on front of his blocks. Then he moved to the track, ignoring an official standing over him with a red card. Then he did a Linford, stalking down the track pulling down his running vest. Then he pulled his kit back up and went as if to resume his blocks for the start.

After two other quarter-finals had taken place the field resumed with two empty lanes, while the screens showed Drummond, who had been talked round by US officials, crying on the shoulder of his coach, John Smith. More booing, to the point where Drummond’s Trinidadian training partner Ato Boldon had to appeal for calm…

If it’s not an obvious flyer, nobody likes a DQ.

In 2010 the rule on false starts underwent another change when the leeway of one indiscretion was abolished after it became clear that some were deliberately triggering it to put pressure on those for whom a fast start was critical. So there was, and is, no hiding place.

The following year I was among those reporting the Daegu World Championships where Usain Bolt, then at the dizzying height of his powers, got it wrong in the 100m final and was disqualified.

It is hard to imagine a more frustrating sporting moment. A whole stadium, millions of TV viewers, all eager to see the jesting and japing subside and the stupendously talented sprinting of the world record-holder and defending champion begin.

And in an instant he is reduced to a shocked and penitent bystander as his training partner Yohan Blake takes his unlooked-for opportunity to win gold.

The situation was similar in Eugene, where Allen was on the brink of doing something that would not only be big in athletics but would - because of his NFL link - reverberate throughout the US sporting world even more strongly than had the previous evening’s clean sweep in the men’s 100m.

It would have been the answer to the World Athletics prayer, a catalyst for growth across the States, spreading the word… all gone in one-thousandth of a second.

Nobody likes a false start.

But there has to be a line drawn somewhere. There has to be a rule, even if you hate it.

And, just as the raft of doping positives over recent years shows the integrity of those who govern world athletics - something that NFL officials might find instructive in some cases - then the fact that Allen, of all people, and at this moment of all moments, was DQ'd speaks also to integrity.

As you would have hoped and expected, Allen, after the understandable shock and dismay, reacted like a sportsman, later tweeting in support of Holloway and fellow American Trey Cunningham, the gold and silver medallists.

"Great job to my boys…1,2 in the hurdles! US back on top!"

But many have been the voices protesting the decision.

It is certainly impossible to detect any false start with the naked eye. Pictures have been posted showing that Allen’s foot actually left the plate after that of Holloway.

Meanwhile the noted US performance coach Steve Magness called the 0.1sec reaction time "a BS rule", adding that it was "completely arbitrary" with no science behind it.

"If this is a false start, then I can fly," tweeted another unhappy viewer. "Idc [I don't care] what the computer says, nonsense."

It’s all absolutely understandable – as long as no one is saying that Allen should not have been disqualified. Excruciatingly close it may have been, but rules cannot be bent if a sport, or indeed a nation, is to retain integrity.

Which doesn’t mean, of course, that rules can’t be changed.

Interestingly Magness brought to notice a story that was posted onto the site of the athletics world governing body - then known as the International Association of Athletics Federations (IAAF) - on July 29 2009, headlined: "IAAF Sprint Start Research Project: Is the 100ms limit still valid?"

"The current false start criterion used by the IAAF is based on an assumed minimum auditory reaction time. If an athlete moves sooner than 100ms after the start signal, he/she is deemed to have false-started.

"The purpose of this study, which was commissioned by the IAAF, was to examine neuromuscular reaction to the auditory signal used in the sprint start and to determine whether the 100ms limit is correct.

"Seven national-level Finnish sprinters took part. A comprehensive approach was used to study force reaction on the blocks, the movements of the arms and the activation profiles of several muscles.

"The authors found great variation in individual reaction times and confirmed previous reports of simple auditory reactions as fast as 80ms.

"They recommend that the 100ms limit be lowered to 80 or 85ms and that the IAAF urgently examines possibilities for detecting false starts kinematically, so that judges’ decisions are based on the first visible movement regardless of the body part.

"This can be done with a system of high-speed cameras, which gives views of all the athletes on the start line. With such a system, it would be possible to change the start rule so that no false starts are permitted."

Discuss.