Hermione explained the night at the Manor, their capture and subsequent escape. The Wizengamot questioned her endlessly on the torture she received under the Malfoy’s roof. It hadn’t been Draco who wielded that knife and it was Draco who didn’t reveal their identities.  When it was Ron’s turn to take the stand, she met Draco’s eyes, and she had no hope of deciphering the look in the depths.