Among the many questions buzzing around Dean Richards' mind after watching his Harlequins team blown off course in the Heineken Cup in Belfast was: when is a replacement not a replacement?
As the game entered a crucial moment with Quins seeking to cut Ulster's lead to three points with eight minutes to go, Richards was left "baffled" by the insistence of the match officials that Chris Malone replace fly-half Nick Evans.
It was a substitution that Quins were seeking to make and the card confirming that had been handed to the fourth official. But when the next break in play brought the visitors a penalty attempt from 35 metres, the last thing Richards wanted to see was his prolific goal-kicker Evans leave the field, having teed up the ball and composed himself to take it.
Yet on Malone had to go and he turned into the pantomime villain, not only pushing the kick wide with his first touch, but moments later was charged down, leading to Rory Best's try that sealed Ulster's victory and denied Quins even a bonus point.
There seems to be no hard and fast rule on the process of getting replacements on the pitch, but French referee Romain Poite called for the change at that next stoppage of play.
"We weren't looking to put Chris on until after Nick has taken the kick, but because we had given the fourth official the substitution card, he and the referee rushed it through," said Richards. "We were surprised to see Chris called on before the penalty was taken but it meant he had to take the kick after only just coming on. We were puzzled."
Ulster's second try, from Malone's mistake, quelled Richards' ire over the confusion but gave fuel to any lingering insecurities within the Harlequins camp.
The Londoners defied the odds with back-to-back wins over Stade Français, but how they react to their first defeat will be just as telling when they face Llanelli Scarlets next week needing a win to qualify to the last eight for only the second time.
"We're disappointed but our destiny remains in our own hands. We're still top of the pool and there's still everything to play for," insisted Richards.
Harlequins will at least be grateful they do not have to face either a rain-lashed Ravenhill or Ulster's Stephen Ferris again.
The icy, 90mph winds and driving rain forced stewards to evacuate the temporary stand in the second half though the Ulster flanker revelled in the conditions, terrorising Quins back-row and three-quarters.
Harlequins allowed themselves to be rattled after Darren Cave strolled through in less than a minute. Nick Easter conceded a further six points while Danny Care saw his third yellow card of the campaign, all in the first half.
Composure returned, for a short period at least, when the might of the scrum was rewarded with a penalty try to narrow the lead to 16-10, only for the game to be effectively sealed by the arrival of Malone.
Ulster: Tries D Cave, R Best; Conversion I Humphreys; Penalties I Humphreys 3. Harlequins: Try Penalty; Conversion N Evans; Penalty N Evans.
Ulster: C Schifcofske; A Trimble, D Cave, P Wallace (B Cunningham, 41), S Danielli; I Humphreys (P Steinmetz, 58), I Boss (P Marshall, 77); J Fitzpatrick (B Young, 60), R Best (capt), T Court (N Brady, 73), E O'Donoghue, R Caldwell, S Ferris, K Dawson (D Pollock, 60), C Henry (M McCullough, 41)
Harlequins: M Brown; T Williams, G Tiesi (E Taione, 51), J Turner-Hall, C Amesbury; N Evans (C Malone, 71), D Care; C Jones, C Brooker, M Ross, J Percival, G Robson, C Robshaw, W Skinner (capt), N Easter.
Referee: Romain Poite (France).Reuse content