Typical. Just when the fiddlers and fumblers of the International Rugby Board were feeling some real heat over their preposterous tinkerings with the law book – revolt in South Africa, fury in France, an embarrassingly lukewarm endorsement from the coach of a Wallaby team meant to be in the vanguard of change and growing evidence in England that it was becoming impossible to stage a game without a penalty-count in the numbers currently being discussed by politicians in Washington – two of London's finest suddenly served up a minor classic. They should be fined heavily and warned as to their future behaviour.
It started encouragingly with a dust-up – Will Skinner, who performed stunningly well for an hour in the Harlequins back row, threw an unusually meaningful haymaker at the London Irish lock Gary Johnson within seconds of the ball descending from the kick-off – and ended thrillingly with one of Skinner's closest comrades, Tom Guest, just failing to hold a difficult pass that might have resulted in the last-chance-saloon try to end them all. In between, there was a proper rugby match conducted in the full glory of the sport's unpredictability.
And the hero of the hour? Step forward Dean Richards. Not the Harlequins version, although the Great Shambling Bear of English union is clearly playing a blinder in driving his club onwards and upwards from the director of rugby's chair, but his exact namesake from the whistling fraternity. Richards the ref controlled the contest in the way contests should always be controlled: pragmatically, sympathetically and with great common sense.
When this match was at its tipping point during the second half, he recognised that both teams were attempting to play positively and allowed them to get on with it with minimal interference. So some people went off their feet at the breakdowns, who gives a damn, apart from a few doctrinaire obsessives in Dublin?
"We all know there are issues with the Experimental Law Variations and the protocols in force at the breakdown, and they haven't gone away," said Toby Booth, the London Irish coach. "But good refereeing is about empathy, first and foremost, and I think we had that out there.
"I understand why the IRB wants people on their feet in the tackle area rather than laying all over the ball, but when, as we did against Bath in our previous game, we make two 90-metre breaks and get pinged for someone going to ground at the final ruck – well, there's no empathy in that, is there? If we want to see attacking rugby, let's help it along by offering some encouragement."
Of course, it is possible that Richards will be chastised for his tolerance rather than congratulated for it. Possible, but unlikely. The assessor in the main stand was none other than Tony Spreadbury, who, during his own long career in the middle, made it his business to referee the game unfolding in front of his eyes as opposed to the game imagined by the law-framers across the Irish Sea. Refereeing is an art, not a science, and the best of it is selective, not comprehensive. Spreadbury must have sensed something of himself in Richards at the weekend.
Quite what Brian Smith, the most recent addition to England's coaching team, sensed as he saw his old London Irish charges fall 20-3 behind in the space of 26 minutes is anyone's guess. The Australian attack strategist has to be more even-handed nowadays, but given the Exiles' intense rivalry with Quins, rooted in decades of close proximity that ended with a bitterly unsatisfactory groundshare arrangement at the Stoop, he would have been less than human had he not fumed ever so slightly during the opening exchanges.
David Strettle, dropped from England's elite squad in July and smarting still, pinballed his way upfield to set up a try in the left corner for Ugo Monye, and when Chris Malone slid the craftiest of kicks into the visitors' 22 off the outside of his right boot, Mike Brown set Guest free for a second try.
Brown then took it into his head to start an argument with both Armitage brothers – rugby's equivalent of picking a row with the Kray twins. Perhaps he assumed the game was already won. Why wouldn't he have done? Everyone else assumed it.
Everyone, that is, except Seilala Mapusua, a Samoan centre very nearly the size of Samoa itself. Even when Quins were rampant and his 14 colleagues were missing in action, he resisted magnificently. When he had some help after the interval, he was better still.
Time and again, he smashed his way upfield to give Irish the right field position from which to launch their attacks, and when possession changed hands, he strong-armed the home side's midfield runners into oblivion.
"We've missed the captaincy of Bob Casey in recent weeks and it was good to be able to bring him off the bench here, but Seilala's leadership has helped us through," said Booth.
"You don't get many pearls of wisdom from him – you'd hardly describe him as Churchill, unless you're talking about the television advert. But he's a 'follow me' man who plays with an enormous amount of heart. I thought he was brilliant."
When they arrived, the Irish points came thick and fast: a penalty from Peter Hewat on the hour, a lovely second try from Delon Armitage two minutes later, an interception score from Hewat four minutes after that and a killer three-pointer off the right post from the same player five minutes from the end of normal time.
Yet Quins dredged their reserves of competitive spirit, responding with a close-range try from Danny Care and then launching one last attack that lasted an age before dying on its feet. It was no more than the game deserved.
Harlequins: Tries Monye, Guest, Care; Conversions Malone 2, Luveniyali; Penalties Malone 2. London Irish: Tries D Armitage 2, Hewat; Conversions Hewat 2; Penalties Hewat 3.
Harlequins: M Brown; D Strettle, G Tiesi, J Turner-Hall, U Monye (T Williams, 77); C Malone (W Luveniyali, 75), D Care; C Jones, G Botha (T Fuga, 68), M Ross (M Lambert, 75), O Kohn (G Robson, 68), J Evans, N Easter (C Robshaw 49), W Skinner (capt), T Guest.
London Irish: P Hewat; T Ojo, D Armitage, S Mapusua (capt), S Tagicakibau; EHickey (E Seveali'i, 45), P Richards (P Hodgson, 51); A Corbisiero, D Paice (D Coetzee, 58), F Rautenbach (T Lea'aetoa, 58), N Kennedy, G Johnson (R Casey, 45), R Thorpe, S Armitage (J Fisher, 79), C Hala'Ufia.
Referee: D Richards (Berkshire).