Compared to a contest that wound up with Collum being singled out as the man who had sabotaged Celtic's push for a first domestic treble since 2001, the more liberal environs of De Kuip probably seemed like a straightforward assignment. Valencia won the match with a 1-1 draw carrying them through to the last eight 5-3 on aggregate, but there remained plenty of moments of aggravation for Collum to negotiate until his final whistle sounded.
With PSV pushing for the two goals they needed to force extra-time, the home side's Swedish forward Ola Toivonen collapsed clutching his head off the ball as if he had been on the receiving end of a Glasgow kiss from the strapping Valencia defender Adil Rami.
Collum would have required eyes in the back of his head to spot such shenanigans, but presumably aided by his two assistants and the odd couple who are perched near each goals on such evenings, Collum probably came to the conclusion that Rami's intimations were not of a sporting nature by brandishing the red card. He awarded a penalty to PSV before altering his decision with Toivonen subsequently booked as Valencia were granted a free kick.
In the closing minutes at Hampden Park on Sunday, there was no such hesitancy in Collum's mind. The Celtic forward Anthony Stokes careered towards the opposition goal with some relish only to be apparently upended by the opposing defender Michael Nelson as he was poised to level matters at 1-1. Amid the groundswell of appeals from the Celtic players and supporters, Collum decided Stokes had taken a dive before booking the forward.
The point of this is obvious: a referee has to call it in the second he sees it. To suggest Collum has some sort of agenda against Celtic is rubbish. Did he have an agenda against Valencia when he opted to red card Rami?
Collum may have been better biding his time in Eindhoven over the weekend with all sorts of nonsense being directed towards the referee, mainly through the anonymous forum of the internet, since his decision not to award Stokes a penalty. Collum, only 33, needs such abuse like a hole in the head. Much has been made of the fact he teaches religious education in a Catholic school. Only in Scotland does such trivia seem relevant.
Collum had nothing to do with Celtic's defeat in the final. Kilmarnock's ability to pass the ball well on the wide open spaces of Hampden Park was heartening. They are an infinitely better side than the Kilmarnock team, captained by the rampaging Ray Montgomerie, who won the Scottish Cup in 1997. Celtic had 94 minutes to overthrow Kilmarnock, but were undone by their own mediocrity. Kenny Shiels's team looked sharper, hungrier and took the one big chance that fell their way on the day.
Kilmarnock would have lived with a number of useful sides such was their hunger not to subside. There is nothing else to read into the outcome of the day. It is always a dicey game to play if a team is relying upon a referee to save a match for them, especially in the death throes of a final.
Celtic have benefited from calls by Collum at other junctures this season. Hearts and Rangers could have scored goals against Neil Lennon's side, but Collum thought otherwise because he was unsure if the ball was over the goalline.
Much has also been made of Celtic manager Neil Lennon's reaction to this decision, but there remain characters who will want Lennon hung, drawn and quartered whatever he does. Lennon embraced Shiels at full-time. His one-sided reaction - describing it as a "criminal decision" - was similar to the stuff you see week in, week out when a microphone is stuck under Sir Alex Ferguson's snout after an adverse outcome. The SFA will decide if he has a case to answer or not.
Until referees are assisted by television replays, decisions will go for teams and against teams. The problem about Sunday's match is that television replays produced inconclusive proof either way. The most important outcome from the day is Collum called it correctly. A fluid Kilmarnock side were hardly fortunate beneficiaries.