It is a year since Martin Keown rounded up a mob of his team-mates to push and jeer Ruud van Nistelrooy back to the dressing-room at Old Trafford after he had missed a penalty. A year since one of their former players, Alan Smith, publicly told his successors that they should "take a long hard look at themselves". A year since the Arsenal chairman, Peter Hill-Wood, informed Arsène Wenger that "there can be no more excuses" for the shower of red cards that the Arsenal manager seemed to accept as a necessary by-product of their success.
It is nearly 10 months since Wenger last had to find an excuse for the dismissal of one of his players - it was Keown again - and another September match day in Manchester provided convincing evidence that all the criticism has produced positive action at Highbury.
Kevin Keegan admitted that when drawing up a list of Arsenal's strengths, "we almost ran out of paper", and resorted to the tactics most managers would employ against the champions: closing down space, denying them time, crowding Thierry Henry, pumping balls towards Jens Lehmann's crossbar and physically intimidating the Arsenal goalkeeper. They worked better than even a natural optimist like Keegan could have hoped.
Although Arsenal still recorded their 11th straight victory against Manchester City, it was harder won than almost any of the others and afterwards Wenger confessed that City had shown a side to their game he did not know existed. From a man who would rival John Motson for an interest in the minutiae of football, that was some compliment.
And yet a year ago, the uncompromising tackling, the sight of bodies clattering into Lehmann, would have produced a reaction from Arsenal and maybe a red card. Arsenal, however, drew not even a yellow from Neale Barry's pocket and it is worth stating that this season they have suffered half as many bookings as their opponents.
"We don't get nervous, we don't get upset, we don't get stupid yellow cards and we deal well with the situation because now we get games that feel like cup-ties everywhere we go," said Wenger. "Even a year ago, we were known for sometimes over-reacting and on that side of the game we have made fair progress.
"We got a big lesson taught by the Manchester United game and, from then on, if you look carefully at our record, we have taken the consequences and learned well. I feel the players have responded remarkably. Jens, a year ago, would not have reacted to the situation like he did today. I give him a lot of credit for that."
For 20 minutes after the interval, Manchester City achieved what few teams manage against Arsenal, pushing them back deep into their own half without leaving themselves open to the lethal counter-attack. But for a sublimely taken goal from Ashley Cole that even his hero, Roberto Carlos, would have struggled to emulate, they would have deserved their point.
And this, of course, neatly sums up City under Keegan. They excelled against potentially the finest team in Europe just as earlier in the month they had collapsed to an earthly Everton side, who would no more attempt Wenger's sophisticated brand of football than Sid James would have embraced method acting.
Keegan, who stated that he would not be playing Robbie Fowler again until the striker had taken time out of the game to improve his fitness, pointed out that while many extol the beauty of Arsenal's play, their strength is often overlooked.
"To go 47 games without defeat, if you are not physically strong, mentally strong, it does not happen. And their goalkeeper is strong; we clattered him, no question," he remarked. "I said to the players afterwards: 'Why not that level of drive and desire against Everton?' But we found out what Arsenal are made of and that's pretty strong stuff."
Goal: Cole (14) 0-1.
Manchester City (4-4-2): James; Mills, Dunne, Distin, Sun Jihai; S Wright-Phillips, Barton, Bosvelt (McManaman, 76), Sibierski; Macken (Flood, 76), Anelka. Substitutes not used : Waterreus (gk), Jordan, B Wright-Phillips.
Arsenal (4-4-2): Lehmann; Lauren, Touré, Campbell, Cole; Ljungberg (Fabregas, 88), Edu, Vieira, Reyes (Clichy, 64); Bergkamp (Van Persie 88), Henry. Substitutes not used : Almunia (gk), Cygan.
Referee: N Barry (Scunthorpe).
Booked: City: Bosvelt.
Man of the match: Cole.