Realising he probably wasn't in the most receptive state, Oliver simply replied with a comforting, 'I'm sorry to hear that, love.' It wasn't a pity reply, either, just honest, supportive. Even if he didn't entirely agree, he would always support Audrey.
'I didn't get to hear what was said. I imagine no one said anything very positive. Which is probably exactly what the Death Eaters wanted. To tear us apart, because if we all stand together we're too strong for them.