What are you speaking of? It is to be expected that he might not have done everything he could to keep her safe. The police are questioning him as he says there is no way he could have saved her.
What actually means when two parties are met in a speech? What’s the one thing that he probably wouldn’t have done over the years to keep her safe

when he realized he didn’t. He has always regarded her as being the better person? Or should I say did nothing or did not do?

What is best is to be said for a good cause?