I think it's good that the father is resisting to leave. Usually we need more than a moment to say goodbye. A wake, for example. Silent hours in which there is nothing more important to do. Yes, a very beautiful and important insight that sometimes you just don't need to say anything and whether a hug or a handshake: they replace these words in a very speaking way. Also to say goodbye to the dead: We all learn.
When my father died, I was confronted with a dead man for the first time. I felt clumsy and insecure. When my mother died, I knew better how to say goodbye.