She declared she had no idea of what the issue was, and then she apologized. I suppose she was sincerely sorry she had caused harm. But if you don't know what you did that caused harm, how can you make certain you don't do it again?
He thanked her for the apology, but let her know he was more interested in getting to a deeper understanding. She wanted to end the issue. He wanted to explore and resolve it at the source. A premature apology can derail learning from each other.
Before you say you're sorry, seek to truly understand what happened. Avoid the perils of a premature apology. Embrace the glories of a well-handled clash of the mindsets.