In The Commuter (2018), the train driver just died. Michael wants to detach the last rail car from a moving train. Sam, the conductor, is already on the last rail car where all the passengers have boarded. He says:
"Between the train and the people, I always knew it would be the train"
and then jumps onto a moving train to get rid of a chain, which happens to be stuck between two carts, aiding Michael, who had already been trying.
What is the meaning of Sam's words?