Hackman is able to live in the moment which means there is nothing for him at that split second than what is occurring in the scene.
If I were to ask you for example right now to go back with me and define those moments in your life that shaped you as a person and you began to reexamine them, something would happen.
There's only one man I've called a coward, and that's Brian Doyle-Murray.
The difference - the fundamental difference between theater acting and film acting is that film acting is disjunctive.