Harry Kane raged that Gabriel's handball fiasco last night was the 'clearest penalty I've ever seen' while his Bayern Munich comrades fumed at a 'stupid' situation.
Arsenal defender Gabriel handled the ball in the second half after David Raya played a short pass to him, with Bayern leading 2-1 at the time.
Refeee Glenn Nyberg had blown his whistle but there was a misunderstanding, with Gabriel thinking he was taking the goal kick.
Nyberg was lenient and allowed play to continue - a decision that sparked wrath on the pitch, on the sidelines, and in Germany - before Arsenal went on to equalise through Leandro Trossard.
'We should have gotten a clear penalty when the referee blew his whistle,' Kane vented.
Harry Kane was livid that Bayern Munich weren't awarded a penalty in the second half against Arsenal
He called Gabriel's handling of the ball after David Raya's pass 'the clearest penalty I've ever seen'
Gabriel thought Raya was teeing him up to take the goal kick and referee Glenn Nyberg let him off the hook - even though he had blown his whistle
'The goalkeeper passed the ball and Gabriel took it into his hands. That’s the clearest penalty I’ve ever seen.'
Bayern had to settle for a 2-2 draw in a thrilling match. Bukayo Saka had put Arsenal ahead in the first half, but Serge Gnabry equalised and Kane put them ahead from the spot.
Muller was seething with the decision to let Gabriel off the hook. He said: 'The referee saw it clearly. The mistake was just too stupid and too petty for him to award a penalty. But he doesn't have to decide that.
'The referee is there to enforce the rules. Even if you may not be satisfied with the rule. I don't think the rule says: OK, if it wasn't intentional, put the ball down again for a goal kick... I don't know what it says. I think it’s a clear penalty.'
Thomas Tuchel was apoplectic when speaking about the referee's allowance for Gabriel, branding Nyberg's justification 'horrible'.
'For me, for all of us, he (the referee) made a huge mistake not giving the handball penalty,' he said.
'I know it is a crazy situation but they put the ball down, he whistles, he gives the ball and the defender [Gabriel] takes the ball in his hand.
‘What makes us really angry is the explanation on the field. He told our players that it is a “kid’s mistake” and he will not give a penalty like this in a quarter-final.
'This is a horrible, horrible explanation. He is judging handballs. Kid’s mistake, adult’s mistake. Whatever. We feel angry because it is a huge decision against us.’
Thomas Muller felt that Gabriel's error was 'stupid' and blamed the referee for ignoring it
Thomas Tuchel was fuming with the referee's decision not to give Bayern a second penalty
Bayern couldn't believe their eyes, while German tabloid Bild said: 'That could have been victory!'
German tabloid Bild felt that Bayern had been robbed, starting their piece on the controversy with the exclamation: 'That would have been victory!'
Even on English shores, the opinion of pundits is that Arsenal - and Gabriel - escaped an ignominious punishment for his mistake.
While Gabriel's mistake was understandable - he obviously just thought Raya was teeing him up to take the goal kick - at the highest level, it is clear he dodged a bullet.
Rio Ferdinand told TNT Sports: 'It's a pen, oh my gosh. How can that not be given?
'I was so adamant that [Bukayo] Saka's one was, I'm even more for this. It's unbelievable. How can he blow the whistle like that and not give it?'
Martin Keown labelled it 'absolutely indefensible', adding: 'The referee is maybe a little bit out of his depth.
'We thought he had a decent game, but there's key moments in the game there both teams can look at.'
If Bayern were furious about that situation, at least Nyberg didn't cave in when Saka went down in the 93rd minute.
Pundits Rio Ferdinand and Martin Keown were in disbelief with the decision after the final whistle
Saka lunged his right leg towards the onrushing Manuel Neuer and went down, and Mikel Arteta marched on to the pitch afterwards to complain to Nyberg.
On commentary, Ally McCoist felt that it wasn't a foul. 'The referee might just have got that one correct, because I don't think Saka needs to throw his right leg into him,' he said.
The Scottish football icon added: 'He definitely got there first, but there's an element, he throws his right leg into him.'
Co-commentator Owen Hargreaves also concurred with McCoist's view of the controversial incident.
However, Ferdinand and Keown disagreed in the studio.
'How has that not been given?' asked Ferdinand. 'With VAR, with everything, I can't believe that's not been given.'
Former Arsenal defender Keown said: 'Neuer is actually going towards that ball, he comes out and makes the challenge. For me that's a penalty all day long.'
At the end of a chaotic game, a scoreline of 2-2 leaves everything to play for in the second leg at the Allianz Arena next Wednesday.
Later in the game, Nyberg ruled in Arsenal's favour when Bukayo Saka went down after colliding with Manuel Neuer
Bayern came into this one on the back of two consecutive Bundesliga defeats while Arsenal are flying at the top of the Premier League.
Bayern's most recent loss was a mortifying 3-2 defeat at the hands of minnows Heidenheim, who overturned a 2-0 deficit in the second half.