Mina watched the other Jeremy and Oric fight in absolute shock. They were not just hitting one another; they were trying to cause severe injuries and the men kept shouting things that she did not understand back and forth. They were speaking the Pan language, but the accusations that were being tossed around did not make sense to her.
Jeremy was accusing Oric of ruining not just his life, but also Willow's. Oric responded by blaming Jeremy's inability to remain faithful. The man quickly followed up by asking Oric if he knew of all the things Willow had to face over the years, and a rage filled Oric threw a punch so hard that it landed with a thud.
Mina knew that Oric was angry because, like her, he likely had no idea of how much Willow had gone through, and it was probably a slap in the face that another man did.