Are there any signs of social oppression in chapter 5 of The Pearl?

At first glance, we can see evidence of gender oppression, especially after Kino basically loses it with Juana and physically assaults her. Juana's reaction is quite telling. It is shocking, because it shows the deeply-rooted ideals that state that men were in charge of women.

He had said "I am man" and that meant certain things to Juana. It meant that he was half insane and half God. . . . Juana, in her woman's soul, knew that the mountain would stand while the man broke himself.

This shows oppression only because, prior to Juana's thoughts, Kino had attacked her, even kicked her, at the thought that she was escaping their home with the pearl.
Still, there is another type of oppression quite evident in chapter 5. When Kino kills the stranger that comes to attack him, he tries to explain over and over that he did this in self-defense. However, Juana mentions a very telling statement:

"Do you remember yesterday?" Juana asked. "Do you think that will matter? Do you remember the men of the city? Do you think your explanation will help?"

Juana's statement brings up that, because of their poverty and their social status, Juana and Kino are disenfranchised. As a result, nothing that they say or do will be believed, accepted, or respected by the "men of the city."
This means basically that there is social oppression, and both Juana and Kino are quite aware of it. For all they know, the "men of the city" could just offer them an insulting amount of money for the great pearl. They could even take it without paying them. After all, the two of them are not considered equals, but are instead considered "lesser" than the mainstream folk.
As such, Juana and Kino are in a situation where, no matter what happens to them, they will end up on the losing end, just for being who they are. That is total social oppression, and nobody deserves that treatment in any civilized society.
http://www.mrlocke.net/EnglishOne/Novel/Pearl/Chapter5.htm