How do Sammy's actions in "A & P" reveal his character? In what ways are his thoughts and actions at odds with each other?

At the end of the story, Sammy quits his job after his manager, Lengel, tells three girls, who have been shopping in their bathing suits, that they need to dress decently when they come into the A & P. Sammy says to Lengel, "You didn't have to embarrass them." It seems that Sammy is quitting out of chivalry, to stand up for the girls who Lengel has judged and disrespected. Sammy's action at the end of the story seems misguided, and his words to Lengel ring hollow, since the readers have seen the way Sammy has judged  other customers and since the reader has heard the objectifying thoughts Sammy has had about the girls.

From the beginning of the story, Sammy has thought of the customers in the store as "sheep," and he has humorously called one lady in his checkout line a witch.

...if she'd been born at the right time they would have burned her over in Salem.

Sammy has also been judging the girls and objectifying their bodies from the moment they enter the store. Furthermore, Sammy has little respect for the girls:

You never know for sure how girls' minds work (do you really think it's a mind in there or just a little buzz like a bee in a glass jar?)

After quitting, Sammy walks outside to see the girls, calling them "my girls." They are gone, and it seems Sammy thinks that his gesture would win the girls, but they don't seem to notice his "heroic" act. Calling them "my girls" further shows his objectification of the girls. It could be argued that Sammy has disrespected the girls far more than Lengel did.