How does saul quick interaction in pic river with father leboutiller impact him? Why do you think saul knows that he will never see him again?

Saul knows this is the last time he will see his old teacher. There is a sense of finality to the encounter. Father Leboutuller has taken Saul as far as he could in hockey. He has also helped Saul escape the evil of residential school. There is however a more sinister force at play that we will not find out about until later in the book.