Mats Hummels left the Allianz Arena with a face like thunder, ignoring all requests for comment. The Bayern Munich centre-back had cut an angry figure for much of his side's 3-1 win over Paris Saint-Germain too.
He wasn't happy with the leniency referee Cuneyt Cakir had shown with regards to some PSG fouls, had frequently shouted at his teammates and raced up the pitch into the opposition box a few times at the end of contest in search of a goal. His demeanour at the final whistle made clear he felt his side had missed an opportunity, regarding the 3-1 win -- two goals short of the required result for topping Group B -- as a defeat.
"Mats is full of ambition," Jupp Heynckes explained in the news conference with a forgiving smile. "Knowing him, he wanted to win 4-1 or 5-1. He's playing outstandingly well at the moment and probably wanted to score [more goals] himself."
The Bayern manager's assessment of the result differed markedly from that of his defender, however. Heynckes was pleased with the "tactically clever" play, the "outstanding way we closed down in midfield" and the attitude, which he described as the "key to success."
The 72-year-old proudly noted, too, that Bayern had shown they could compensate for the loss of key personnel in Manuel Neuer, Thiago and Arjen Robben.
Thomas Muller's take was more nuanced. The forward explained that Bayern had been torn between going for a bigger victory and ensuring they would actually win the game, as Heynckes had mandated.
"We subconsciously decided to make sure we won. But ultimately, that doesn't really get us much," Muller said, unsure about the benefit of the result. He added that PSG had been praised too highly after Bayern's 3-0 defeat in Paris in September by the German media: "They don't have a magic potion."
We will only know after the round-of-16 draw on Monday whether regret (Hummels), satisfaction (Heynckes) or a combination of both (Muller) will be the prevailing feeling in Munich.
Finishing second might not turn out a huge disadvantage if they were to draw Roma or Besiktas, for example. But in any case, it will be noted in Bavaria the German champions have not been able to win their group for the second consecutive time after an uninterrupted run of five years as first seeds. The difference might only be minute, but it's nevertheless telling, at this level. Bayern have ever-so-slightly dropped in performance since Pep Guardiola left his post.
Tuesday night holds out the promise this relative slump can be reversed, at least partially. Bayern's controlled, quietly aggressive and efficient game-plan, vaguely reminiscent of their counter-attacking tactics against Barcelona in the 2013 semifinal, proved beyond doubt that this squad remains competitive at the highest level when properly coached and motivated.
The board will have been particularly delighted to see some of the more recent recruits, Sebastian Rudy, Colentin Tolisso and Niklas Sule, hold their own against the star-studded visitors. Critics (including Robert Lewandowski) had wondered whether the cautious transfer strategy had depleted the overall firepower too much for the challenge in Europe. The win against PSG, without the aforementioned out of commission stalwarts and key players like Jerome Boateng, Arturo Vidal and Muller in the starting XI, suggests the side's individual quality has probably been under-estimated in light of 18 months of mostly disjointed showings under former boss Carlo Ancelotti.
Collectively, there's clearly a lot of potential that has gone untapped. As Heynckes noted on the eve of the game, teams need to have a strong group ethos and a degree of dressing room harmony to succeed. That's even truer of a side like Bayern who can't count on the services of two or three superstars. They, unlike, say PSG, will only win against top opposition if they're a functioning, spiritually and tactically united collective.
Employing the sort of counter-pressing that so successfully prevented most counter-attacks from the Parisians needs both exact planning as well as unselfish camaraderie and application. Tactics, attitude and hard work blend into one. And Heynckes looks uniquely positioned to coax it all out, with his characteristic calmness.
All practical implications aside, it was a good night for the optimists in Munich, for all those who believed the loss of form under Ancelotti was temporary and reversible rather than a terminal decline.
There'll be bigger tests in store than a curiously passive PSG side, no doubt, and Bayern will have to improve much more to get even close to a final appearance in Kiev.
But there's no question the direction of travel is hugely positive. The confidence is coming back, and with it, some status. "We're still FC Bayern," Muller exclaimed defiantly.
For the club's self-conception, this was a big win.