I haven't bothered to watch either programme and doubt if I will, but was fascinated to learn that by the lawyer's language as reported in the Daily Telegraph. After announcing that the Sussexes did not take a vow of silence and become like Trappist monks (if only), therefore not allowed to discuss anything.
What bullying means, apparently is "improperly using power repeatedly and deliberately to hurt someone physically or emotionally, and the D of S has absolutely denied ever doing that. That said, she wouldn't want to negate anyone's personal experiences." But "it is really hard to prove a negative, and to show you had not bullied someone by denying it."
Particularly when they have made formal complaints and are anxious to give evidence.