It looked, for a moment, like the perfect delivery. Not just a perfect delivery, but a perfectly executed plan.
Jack Leach, bowling round the wicket, had drawn Steve Smith forward and, having found just a little drift into him, gained just enough turn away from him to see the ball take the edge of the bat and carry to slip. Smith had already scored 118 by then but, such is his form and so great his dominance, England might have settled for that. Besides, Australia were 273 for 6 and England could, perhaps, anticipate bowling them out for little more than 320.
But then came the replays. And after that came the realisation. Leach, despite the most gentle of run-ups, despite bowling at a 51 mph, had over stepped. Smith was reprieved and England's joy turned to despair. We may look back on it as the tipping point in this series.
Maybe that's unfair on both Leach and Smith. Certainly Leach, at times, bowled really nicely. His misjudgement was, it its way, tiny: no more than a rash shot from a batsman or a dropped catch from a fielder. But the consequences were significant and it was avoidable. An unforced error, as they say in tennis.
Most of all, when we come to reflect on this series in years to come, we'll almost certainly conclude that the difference between the sides was one man: Smith. England have thrown pretty much everything they have at him in not just this series but the previous couple. The fact is, while most other batsmen have struggled, Smith has gorged on runs. Yes, the pitches might have offered England more assistance. And yes, James Anderson's availability might have tested Smith more. But to a large extent, England just have to accept he has been too good for them.
There will be nagging irritation, however, that England did not do themselves justice. For there were moments on the second day when they became more than a little ragged in the field. Tim Paine was also reprieved twice - he was dropped on 9 and 49, once at slip by Jason Roy and once at mid-on by substitute fielder Sam Curran; both relatively straightforward chances - with Jofra Archer also missing a tough caught and bowled chance offered by Smith when he had 65. England keep dropping catches. Leach's no-ball is a symptom of a wider malaise.
Most of all, England didn't seem able to build or sustain pressure in the field. With Ben Stokes, suffering from a sore shoulder, unable to replicate the match-shaping spell he produced in Leeds and Smith managing to manoeuvre the ball into the gaps with his unique skill, England leaked 124 runs in 32 wicketless overs after lunch.
Archer, only five months into his England career, already looks as if he is in danger of being ruined - news that he required a pain-killing injection after normal play in the World Cup final and before the super-over should have alarm bells ringing - with his pace dropping by the match. Not for the first time in this series, it seemed England's captain, Joe Root, had no way of lifting his team and no answers to the questions raised by Smith. It was agony from an England perspective; a session where you could feel their Ashes hopes slipping away.
And then there's that no-ball. Spinners - certainly finger spinners with a gentle approach to the crease, shouldn't be bowling no-balls. Ravi Ashwin, for example, has never bowled a no-ball in Test cricket. And while Moeen Ali has, they have all been head high full tosses rather than front-foot no-balls. In all, finger spinners have, on average, bowled one no-ball - including head-high no-balls - every 1,236 deliveries in Test cricket since the start of 2010.
So while we must be careful not to pin too much blame on Leach - he's not responsible for England's enduring inability to bat, or catch, after all - we can't just dismiss it as 'one of those things.' That's too cosy; that's too laissez-faire. For we know that, in ODI cricket, England went more than 10,000 deliveries without conceding a front-foot no-ball. We know that, if there are free-hits at stake and they make it a priority, it can be done. But in training in recent days, England's bowlers have regularly over-stepped in the nets without any of the coaching staff acting as umpires and notifying them of their error. As a consequence, instead of good habits becoming ingrained, bad habits can take root. It seems just a bit sloppy and just a bit unnecessary. The team management have to take some responsibility.
England's issues extend beyond playing matters. At some stage, if England are to make any meaningful use of home advantage, Ashley Giles, the director of England's men's cricket, will have to improve the communication between the team and the groundsmen.
England turned up in Manchester expecting to find a hard pitch offering pace and carry. Just as they turned up for the World Cup final expecting a batting paradise. On both occasions - and several more in between - they have been disappointed. Indeed, one member of the England team management noted that this surface - offering little of the grass coverage that might have encouraged England's seamers - would have delighted Australia. If England are to have any hope of dismissing Smith, they require lateral movement and the carry to ensure nicks make it to slip. They didn't really have either here.
Everyone understands that the job of groundsmen is desperately tough, with poor weather and an unrelenting schedule combining to reduce preparation time. But at some stage it would surely make sense for the left hand to know what the right hand is doing in English cricket. It would surely make sense for Giles to make it clear what groundsmen are expected to provide and hold them accountable if they do not.
England's Ashes hopes aren't over yet. Not quite. They only need to escape with a draw here to make it to The Oval with their chances alive and it may well be that poor weather comes to their aid. But, for the second Test in a row, you get the impression they're going to require something special to keep them in it. They can't keep expecting Stokes to bail out their substandard batting and fielding.