Board Thread:Speculation House/@comment-158.125.243.29-20150329080244/@comment-4010415-20150416162518

The argument was mostly about the White Fang, with Weiss' view being that they're a criminally insane group of degenerates and Blake arguing that they're not. Them arguing specifically about the White Fang itself happens multiple times throughout their argument. Such as, when the argument first gets sparked by the idiot cops naming the White Fang as suspects of the Dust shop robbery:

Weiss: "Hmm! The White Fang." (crossing her arms and pointing her nose in the air with her eyes closed) "What an awful bunch of degenerates!"

Blake: "What's your problem?"

Weiss: (turning to her) "My problem? I simply don't care for the criminally insane."

Blake: "The White Fang is hardly a bunch of psychopaths." (crossing her arms, getting serious) "They're a collection of misguided Faunus."

Weiss: "Misguided? They want to wipe Humanity off the face of the planet!"

Blake: "So then they're very misguided. Either way, it doesn't explain why they would rob a Dust shop in the middle of downtown Vale!"

Ruby: "Hmm... Blake's got a point. Besides, the police never caught that Torchwick guy I ran into a few months ago... Maybe it was him."

Weiss: "That still doesn't change the fact that the White Fang are a bunch of scum." (to Blake's growing anger) "Those Faunus only know how to lie, cheat, and steal."

"Those Faunus," in reference to the Faunus in the White Fang. After chasing and losing Sun, they argue about whether or not it's wrong to call him a rapscallion and whether or not it's wrong to just assume that Sun will eventually join the White Fang just because he broke the law.

When they get back to the dorm, the argument returns to being specifically about the White Fang.

Weiss: (getting up from her bed) "You realize you are defending an organization that hates Humanity, don't you? The Faunus of the White Fang are pure evil!"

Blake: (gets on her feet as well) "There's no such thing as pure evil! Why do you think they hate Humanity so much? It's because of people like Cardin, people like you, that force the White Fang to take such drastic measures!"

Weiss: "People like me?"

Blake: "You're discriminatory!"

Weiss: "I'm a victim!"

Weiss is mad at Blake for defending a pure evil organization that hates humanity, especially because Blake insists that it's humans who force the White Fang to take drastic measures. Weiss then gives her monologue about how the White Fang's actions affected her home life, about how the White Fang were responsible for the disappearances and executions of people she knew. She doesn't particularly trust Faunus in general because she can't tell which ones might be members of the White Fang. It would be especially interesting if one of the Faunus employees at the SDC once turned out to be an undercover White Fang member and attacked her.

After her monologue, she speaks specifically about the White Fang: "You want to know why I despise the White Fang? It's because they're a bunch of liars, thieves, and murderers!"

So, I'll reiterate. Most of the argument was about the White Fang. Due to that being the prevalant subject of their argument with Blake trying so hard to defend the White Fang, it was very reasonable for Weiss to assume "we" meant "the White Fang," not just Faunus.