Football referee Deniz Aytekin referred to his discretion in the discussions about a possible dismissal for Dortmund's Jude Bellingham in the 2-2 draw against Bayern Munich.
"Jude doesn't do it on purpose, even when it comes to contact.
As a referee, you think: Do I still have some leeway?
It was there for me," said the "referee of the year" at Sport 1.
Bellingham hit Bayern player Alphonso Davies in the head with his foot just before half-time.
The Canadian international then had to be taken to the hospital.
With Dortmund's Bellingham already charged with a yellow card, Aytekin could have sent off the England international.
"Individually, this is theoretically a card, but in the game with the overall situation" there is scope that "you have to use from time to time," said the 44-year-old.
"I absolutely understand every Bayern fan who looks at the situation in isolation: That's a yellow card."
Kahn and Nagelsmann disagree
Aytekin received encouragement from former Munich CEO Karl-Heinz Rummenigge.
"If I'm honest, I'm also a bit with the referee and I understand that he didn't want to finally bring the stadium to a boil.
It would have been a tough decision to send him off with yellow and red," said Rummenigge on TV broadcaster Bild am Sonntag.
Bayern coach Julian Nagelsmann, on the other hand, showed no understanding at all.
"There's not much to discuss about that.
He kicks him hard in the face.
It's not yellow, it's a red card," the coach said on Sky TV.
Oliver Kahn also spoke up on Twitter: "Where was Deniz Aytekin's empathy with the yellow-red card for Coman?" asked the Bayern CEO.
Coman was sent off with a traffic light card after a tactical foul in the 90th minute.