Steph Njuguna has been captured viciously attacking her boyfriend Jeffrey Ndegwa for breaking up wit.
But he did not do so in August when it mattered most, legal counsel for the SA Police Service, Ishamel Semenya, argued.
During cross-examination, Semenya asked Mathunjwa for his stance on the "armed protests" and "unlawful killings".
In response Mathunjwa said he was against protesters carrying weapons and that he was against any sort of violence.
Semenya presented a video clip that captured a group of miners clearly disobeying a police instruction to disarm.
Though the footage also shows the miners claiming the weapons they were carrying were for protection, they did not signal any intent to wage war, Semenya argued.
Referring to the clip, Semenya asked: "Have you ever condemned the armed protest of your members?"
Mathunjwa replied that he had on numerous occasions condemned all acts of violence.
The commission continues today.