Borussia Dortmund succumbed to a 3-2 defeat at home to rival Bayern Munich, with the second half seeing controversial penalty decisions go in favour of Die Roten.
Firstly, Marco Reus's protests were ignored when the Dortmund man was tripped in the Bayern box by Lucas Hernandez, before the visitors got their winner in similarly contentious fashion.
❌ NO PENALTY!! What do you think? The hosts are NOT happy 😡@BVB 2-2 @FCBayern— beIN SPORTS (@beINSPORTS_AUS) December 4, 2021
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Mats Hummels threw himself between two players in an attempt to reach a corner delivery, but he appeared to start stumbling and ultimately fell into the ball with his arm first.
While replays showed Hummels was not looking at the ball, seemingly rendering it accidental, Zwayer pointed to the spot following a VAR check and Robert Lewandowski subsequently scored what proved to be the winning goal.
⚽️ GOAL!! Insult to injury for @BVB, given no VAR was used earlier for its own penalty appeal.@BVB 2️⃣-3️⃣ @FCBayern— beIN SPORTS (@beINSPORTS_AUS) December 4, 2021
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Bellingham suggested it was the standard of refereeing to be expected from someone who had "match-fixed" before, alluding to controversy earlier in Zwayer's career.
However, Zwayer has never been found to have fixed a game.
In 2005, Zwayer was caught up in a scandal that centred around fellow referee Robert Hoyzer, who was found to have fixed matches in Germany's second tier, 2.Bundesliga.
In one match, Zwayer was Hoyzer's assistant and was accused of taking a €300 ($480) bribe before he and three others turned Hoyzer in.
Zwayer faced a German FA (DFB) disciplinary over the matter in 2006. In December 2014, German newspaper Die Zeit published documents that showed Zwayer was banned for six months, information that did not emerge at the time.
Bellingham told Viaplay Football after Dortmund's defeat: "For me, it wasn't a penalty, you know? Hummels is not even looking at the ball, and he's fighting to get it.
"It hits him and I don't think he's even looking at the ball. You can look at a lot of the decisions in the game.
"You give a referee that has match-fixed before the biggest game in Germany, what do you expect?"
Erling Haaland was similarly uncomplimentary about Zwayer, but just about managed to keep his anger in check.
"I think it was a scandal when it comes to the referee," he said.
"Clear penalty [on Reus]. I asked [Zwayer], 'Why didn't you just go and look?'. He said, 'There's no need.' Arrogant ... no, I have to calm down a little bit now.
"He was arrogant and I will not say more."