Dortmund fans left the stands during the game on Saturday to signal their unhappiness with the club's current ticket pricing structure
Dortmund's long unbeaten streak came to an end at the Imtech Arena, after goals from Son Heung-Min and Ivo Ilicevic, but there was more than one talking point after the game.
Coach Jurgen Klopp admitted afterwards that he sympathised with the fans over their concerns, and took the time to urge the club's board to come to a compromise over pricing.
"Who knows what these people endure to be here and support us in the stadium?"
"If then 1,000 fans leave the stadium, I guess their concerns are quite big. We all have to be careful, that's clear, not to make things worse, there have to be talks.
"Either they [the talks] were of no avail or have not taken place up to now. I can really understand the protest," he told Ligatotal.de.