I answered their questions 'to the best of my knowledge'. [=I gave the best answers I could based on what I knew, but I might have answered differently if I had known something else]
No one arrived late 'to my knowledge'. [=I am not aware that anyone arrived late, but it is possible that someone arrived late and I don't know about it]
They went on vacation, 'safe in the knowledge' that the farm would be well cared for while they were away.
(..) candid you are here today, I may be able to keep you in Pakistan. What do you want to know? I'm gonna ask you a series of questions, based on your knowledge of al-Qaeda, and your position as key financier for the organization. I have dealt with the horrors. I have no wish to be tortured again. (..)2012 Zero Dark Thirty