Out of a chaotic but utterly compelling night at the Bernabeu, there were many questions, but one of the most pressing beyond those about refereeing decisions was this: did the most ‘deserving’ team go through? The second most pressing was would the most ‘deserving’ team have gone through even if every refereeing decision had been right?

That kind of unpredictability is one of the great glories of the football, and Real Madrid’s 4-2 win over Bayern Munich on Tuesday night was genuinely close to being one of the modern Champions League’s truly epic encounters.

But it also summed up so many of the frustrations of the modern game. It was an intense and hugely entertaining encounter, but still one irritatingly decided by a series of conspicuously questionable decisions as much as the great players present like Cristiano Ronaldo and Arjen Robben.

Real Madrid 4 Bayern 2 player ratings Show all 22 1 /22 Real Madrid 4 Bayern 2 player ratings Real Madrid 4 Bayern 2 player ratings Keylor Navas – 6 out of 10 Found wanting when called upon. Should have done better to prevent Ramos’ own goal. Real Madrid 4 Bayern 2 player ratings Dani Carvajal – 7 out of 10 His early effort from range may not have gone in but it set the tone for Madrid to have the better of the first half. Real Madrid 4 Bayern 2 player ratings Nacho – 7 out of 10 More solid than his defensive partner, and looks to be benefitting from gaining Zinedine Zidane's confidence. Real Madrid 4 Bayern 2 player ratings Sergio Ramos – 6 out of 10 Unfortunate to divert the ball into his own net, but it could have been avoided with a little more communication. Real Madrid 4 Bayern 2 player ratings Marcelo – 9 out of 10 Excellent. Superbly blocked Thiago’s effort early on, then produced a brilliant goal-line clearance after the break to deny Robben. Impressed going forward too, setting up Ronaldo in extra time. Real Madrid 4 Bayern 2 player ratings Luka Modric – 7 out of 10 Key to Madrid’s excellent spells of first half build-up. Ronaldo should have rewarded one particularly special pass with the goal it deserved. Real Madrid 4 Bayern 2 player ratings Casemiro – 7 out of 10 Careless in his challenge on Robben for the penalty. Otherwise, a solid presence disrupting Bayern’s forays forward. Real Madrid 4 Bayern 2 player ratings Toni Kroos – 5 out of 10 Struggled to match the influence of his fellow midfielder Modric. Real Madrid 4 Bayern 2 player ratings Isco – 6 out of 10 Failed to build on Saturday’s excellent showing at Sporting. Real Madrid 4 Bayern 2 player ratings Karim Benzema – 5 out of 10 Offered very little before being hauled off for the more impactful Asensio. Real Madrid 4 Bayern 2 player ratings Cristiano Ronaldo – 8 out of 10 A quiet start but then came another ‘clutch’ goal, just like his two in Bavaria. Two more followed thanks to poor officiating, but this was still a reminder that you should never write Ronaldo off. Real Madrid 4 Bayern 2 player ratings Manuel Neuer – 6 out of 10 Will be disappointed to have conceded six over the two legs, but was outdone by some poor officiating here. Real Madrid 4 Bayern 2 player ratings Philip Lahm – 6 out of 10 Struggled to cope with Marcelo, who got the better of him too often. We have come to expect more. Real Madrid 4 Bayern 2 player ratings Jerome Boateng – 7 out of 10 Heroic block on the line stopped Ramos from putting the hosts in front in the first half. Real Madrid 4 Bayern 2 player ratings Mats Hummels – 8 out of 10 Another defender who put his body on the line when it counted. Spectacularly blocked Kroos’ shot in the first half. Real Madrid 4 Bayern 2 player ratings David Alaba – 5 out of 10 His poor crossing let his teammates down when they were making headway early on. Real Madrid 4 Bayern 2 player ratings Xabi Alonso – 5 out of 10 Surprisingly poor in possession during his last Champions League appearance, with several wayward passes. Replaced by Thomas Muller deep into the second half. Real Madrid 4 Bayern 2 player ratings Arjen Robben – 8 out of 10 Made things tick in Bayern’s attack. Questionable role in the penalty, maybe, but his side's stand-out performer still. Real Madrid 4 Bayern 2 player ratings Arturo Vidal – 4 out of 10 His tackle was fair and should not have resulted in a red, but still, too often a liability. Should also have done better when slipped in by Robben soon after Bayern’s first goal. Real Madrid 4 Bayern 2 player ratings Thiago – 5 out of 10 Off the pace in the opening stages and failed to grow into the game. Real Madrid 4 Bayern 2 player ratings Franck Ribery – 5 out of 10 A fading force, unfortunately. Simply did not trouble Madrid’s backline with the regularity of Robben. Withdrawn for Diego Costa. Real Madrid 4 Bayern 2 player ratings Robert Lewandowski – 6 out of 10 Not his best night, despite cooly converting the penalty.

Granted, one of the biggest wrong decisions was arguably that of an understandably seething Carlo Ancelotti himself, in keeping Arturo Vidal on the pitch when he looked a red card waiting to happen.

The Chilean did get sent off of course, but not for a tackle that was a foul, and that was the big frustration in this up-to-then uplifting game.

At that point in the 84th minute, it was an encounter so enticingly on the edge and in the balance. Bayern had scored the goal to bring them level, and it looked set for an immersive extra-time, one of those nights where every single player is so intensely invested and aware of both the stakes and exhausting this was.

That should have been the stage for the great players to decide things with their sensational ability. While that happened to a certain degree with Ronaldo's goals, what facilitated that was some sensational mistakes. Vidal should never have gone - at least for that specific tackle on Marco Asensio.

He could well have gone before then, and that reflects that were likely possible wrong decisions before that. Zinedine Zidane was keen to point out after the game that Bayern’s second was likely offside, although that might well have been offset by Robert Lewandowski then getting incorrectly flagged when clean through, and that Casemiro could also have gone off.

Arturo Vidal's red card was one of a number of controversial incidents (Getty)

As Ancelotti also pointed out, though, you can usually understand a lot of these decisions because there is enough room for doubt. People accept understandably incorrect calls.

“I know it’s football and it happens sometimes,” the Italian began. “But not this serious of a mistake.”

And that was the thing. The Vidal decision wrongly ruined how beautifully poised the game was. The next few decisions, that were even more obviously wrong, went and decided the game. Ronaldo scored two goals from blatantly offside positions.

It does seem misplaced that a match of such magnitude and involving such intense effort from the players can be settled in such a literal arbitrary way. It does at least strengthen the argument for continued experimentation with video technology, even if there are remaining issues and fair questions over the speed of the system used in the recent France-Spain friendly.

The irony is of course that referee Viktor Kassai was the official who was in charge of that game and used the technology to get two big calls completely right. He might well think he could have done with it here, as Ancelotti argued, having first questioned the referee’s performance.

"A quarter-final, you have to have a referee with... I don't know... with more quality. Or have video. There are too many errors.

Carlo Ancelotti was left fuming with the decisions made against his team (Getty)

“The ref had a bad game. Full-stop.”

Bayern are out. Well, not quite with a full-stop but with a lot of questions about the decisions.

It happens in football. That is something you generally have to accept.

It rarely happens to this degree. That is something you can understand them struggling to accept.

It is also such a pity that a match that had all the ingredients in place to be a pure football epic ended up being just one other massive and tedious argument about officiating.

So, did the most deserving team go through? That is hard to say, but not being able to say it is usually one of the beauties of football; one of its great virtues.