the dad just want her to speak. Until now he never listen to her since she was a "problematic child". But from the start of the story she behave differently, she didn"t try to explain herself anymore and just ask to be punished instead. He thaugh he maybe was to strict or to quick to jugde and try to know her version of the story before acting for once.
After, you have half-true, he did know but only what the servents told him. They never said anything who put themself in the wrong. That the servents method to misstreat her since the dad never listen to her anyway. But because of the cutlery case, the father didn't have a blind faith on the servents anymore.
Bref, he know she ask eclise to kill another knight and he know the knight wasn't really nice to eclise too. But he didn't know the knight insult Peneloppe.