Simon Grayson classed Leeds United's concession of a two-goal advantage on Boxing Day as one of those things.
The loss of two identical leads on the same afternoon yesterday was nothing of the sort.
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Shocked faces were everywhere at Elland Road after the club's frantic draw with Portsmouth.
Twice Leeds had the beating of the one Championship team they had not confronted in 23 previous fixtures and still two points went begging, as they had at the Walkers Stadium on Sunday.
The protagonists of their misfortune were Andy O'Brien, the scorer of an own goal in injury-time, and David Webb, a referee whose feeble authority invited a riot.
Webb's influence was causing unrest on the terraces long before O'Brien reached out with a leg and turned a cross past his goalkeeper, Kasper Schmeichel, but the performance of the Lancashire official was something which Grayson expected to mention in passing afterwards.
It instead became a dominant issue, alongside the admission from United's manager that his team should have put Portsmouth to the sword regardless.
Leeds scored twice in the first 10 minutes and led 3-1 with over an hour played.
As pivotal as O'Brien's mistake or Webb's ineptitude was United's failure to defend the lead given to them by Bradley Johnson's 62nd-minute goal for more than 60 seconds.
The effect of Webb's officiating grew in negativity throughout the match, culminating in a mass of unpenalised fouls that had Grayson screaming in uncharacteristic fashion at the fourth official.
Portsmouth were not immune to Webb's errors of judgement but they were grateful for his refusal to award a penalty after Ibrahima Sonko flattened Ross McCormack while Leeds fought to insure themselves against a late equaliser.
A subsequent finish from McCormack found Webb more willing to identify a foul.
McCormack was part of United's starting line-up and a good example of the strength of their squad, the ace up Grayson's sleeve for what remains of the Championship season.
He reshaped a team unbeaten in 10 league games and came within two additional minutes of completing his business as intended, in the form of a precious win over opponents with more meagre resources.
Teams with as much impetus as Leeds do not invite a change of personnel and Grayson is never profligate with places in his line-up, but he saw sense in an exchange of shirts yesterday.
Unlike his counterpart, Portsmouth's Steve Cotterill, his alterations were not borne out of necessity.
Dropped to the bench were Luciano Becchio, Leeds' leading goalscorer, and Neil Kilkenny, a midfielder who had started all 10 of the matches completed by United without defeat
A fresh outlook was logical so soon after the club's Boxing Day fixture but there was a tactical feel to Grayson's approach. He could almost be heard turning the screw and his chosen side did likewise in the opening minutes.
Billy Paynter took Becchio's place and Kilkenny made room for another striker in McCormack, leaving no question about Grayson's interest in winning the game.
He was not alone in believing that a draw was beyond Portsmouth when Johnson buried a volley midway through the second half, but the visitors' persistence was admirable.
To accommodate McCormack, Jonathan Howson was evicted from the attacking position adopted by him ever since United turned the corner in late October. The midfielder scored nonetheless, three minutes after
Max Gradel's opening goal and 10 minutes into the match.
Grayson thought by then that his approach had worked, and a seventh home victory was United's to lose. But the lesson of Leicester, where a 2-0 lead escaped Leeds in the final 19 minutes, was put to less-than-perfect use, and O'Brien's unintentional touch sold a result of immense value against an unpredictable team. Portsmouth were not, by Grayson's estimate, a step down from the class of Leicester but squad rotation is a concept that Cotterill can scarcely embrace.
The lingering effect of the club's insolvency is a squad of 19 professionals, three of whom were unavailable at Elland Road. Their bench contained only five players, a keeper among them.
Cotterill might expect much of his strongest line-up but Portsmouth are the sort of club most likely to suffer at a juncture when two games fall in the space of 48 hours. The players missing from their squad yesterday – Michael Brown and Liam Lawrence – are crucial cogs in a fragile machine and one which United set about dismantling.
McCormack's undefined role was a mystery to Portsmouth's defence for long enough for Leeds to score twice, and the damage inflicted on Cotterill's side in the early exchanges appeared to be fatal.
Gradel instigated the flurry, as he has so often in the past two months, and Howson's finish offered protection against a classy reply from David Nugent.
Nugent's strike was a short flicker of class from a forward who once merited a valuation of 6million and it kept Portsmouth afloat.
Paynter cost Leeds considerably less in July and has contributed little since then, constrained for many weeks by a fractured shin.
His outing was almost the shortest imaginable after an awkward fall left him flat on the ground seconds into the game but he shook his head clear and opened the way for Gradel's goal, scored after only seven minutes.
Paynter's attempt at a diving header failed to redirect Paul Connolly's cross but his presence pulled markers away from Gradel who swept the ball past Jamie Ashdown at the far post. The floodgates opened instantly.
Three minutes later, McCormack's cross-field pass fell to Howson via the head of Snodgrass and United's captain drifted quickly through half-hearted covering from Carl Dickinson and Aaron Mokoena. Unimpeded on the penalty spot, his curling shot beat Ashdown easily.
Cotterill sensed defeat in the air and could only reflect that Portsmouth should have struck before Gradel.
Their first attack found Leeds short of numbers inside their own half and Nugent's measured pass to John Utaka was an invitation to score.
The midfielder saw his chipped shot strike the left hand of Schmeichel who ran from his line to make a crucial touch which Webb failed to spot.
It was Portsmouth's chance to ruffle Leeds, but other opportunities took time to arise. United's fluid attacks stretched Cotterill's defenders to the point of collapse, and a bobbling ball prevented Paynter from turning McCormack's clever back-heel into the net with 23 minutes played.
But the sting of United's pressure faded around the half-hour and Nugent's effort in the 33rd minute was in the post for some time before it arrived.
Dave Kitson hooked an overhead kick wide and saw a header cleared off the goalline by McCormack before Nugent drifted onto Hayden Mullins' pass and stroked the ball into the roof of Schmeichel's net.
Leeds were embattled for the remainder of the half but a Snodgrass cross almost tempted Mokoena to head the ball beyond Ashdown.
The Scottish winger resumed his merciless torture of Dickinson in the first minute of the second half by skipping around the left-back and drawing a parry from Ashdown.
Cotterill made his first attempt to influence the match on the hour when he replaced his limping right-back, Joel Ward, with the aging Kanu, and Sonko joined the striker in no time at all.
Chaos ensued as Johnson smashed a volley through Ashdown's left hand on the rebound from Snodgrass' corner and Richard Hughes replied in the blink of an eye, driving home Kanu's cut-back with the help of a deflection off the legs of O'Brien.
Grayson has come to expect the frantic in an unbeaten run spanning two months and he watched with anxiety as Schmeichel parried Hughes' volley and Johnson escaped with a dangerous back-pass.
But when Cotterill's final substitute, Nadir Ciftci, caught United left-back George McCartney absent without leave, O'Brien was drawn into stretching for a low cross which Schmeichel appeared to have covered.
Not on this occasion could Grayson find great solace in a point when asked to assess the two he had lost.
Leeds United: Schmeichel, Connolly, O'Brien, Collins, McCartney, Snodgrass, Howson, Johnson, Gradel (Sam 81), McCormack, Paynter (Becchio 65). Subs (not used): Higgs, Bruce, Kilkenny, Hughes, Somma.
Portsmouth: Ashdown, Ward (Kanu 59), Mokoena, Rocha (Sonko 60), Dickinson, Halford, Mullins, Hughes, Utaka (Ciftci 88), Kitson, Nugent. Subs (not used): Flahavan, Hriedarsson.
Referee: D Webb (Lancashire).