Some jobs can't wait for another day, they have to be done now. And if it is sinful for me to work on the Sabbath, then it is sinful for my neighbor to do so as well. Regardless of a persons religious faith, sin is sin.
There are many practical lessons in the Word of God. . . . In the parable of the Good Samaritan, Christ showed who is our neighbor. The priest and Levite, whose duty it was to minister to the needs of the stranger, passed by on the other side.
I suspect they justified their choice by saying to themselves "there will be plenty of other people who will do just as good of a job as I would."
Christ denounced every form of hypocrisy, and He fearlessly exposed it. He said that there is more hope for the open sinner than for this class of pious hypocrites.