What is the significance the hitchhiker's comments?

Near the end of the story, Mr. Shiftlet leaves Lucynell asleep at a diner. He claims that she is a hitchhiker. He drives down the road, and he is feeling quite depressed. Mr. Shiftlet sees a young boy on the side of the road, and he offers the boy a ride. 

"Son," Mr. Shiftlet said, "I see you want a ride."
The boy didn't say he did or he didn't but he opened the door of the car and got in, and Mr. Shiftlet started driving again.

Mr. Shiftlet then goes on to explain how great mothers are. He is trying to convince the boy that running away from home isn't the answer. He's also trying to come across as a man made wiser by the same experience of running away. Mr. Shiftlet gives a great testimony about how he regrets leaving his own family. 

"I never rued a day in my life like the one I rued when I left that old mother of mine."
The boy shifted in his seat but he didn't look at Mr. Shiftlet. He unfolded his arms and put one hand on the door handle.
"My mother was a angel of Gawd," Mr. Shiftlet said in a very strained voice. "He took her from heaven and giver to me and I left her." His eyes were instantly clouded over with a mist of tears. The car was barely moving.

Mr. Shiftlet is coming across like a wonderful man that has nothing better to do than look out for the welfare of this young boy; however, the boy is able to do what Lucynell's mother was unable to do. The boy is able to see through Mr. Shiftlet's web of lies and flowery talk. Additionally, the boy has the courage to call out Mr. Shiftlet as the hypocrit that he is.