User blog comment:The Devil's Advocate WP/Weiss is actually the nicest member of Team RWBY/@comment-18396318-20131002032159/@comment-18396318-20131003020447

The fact that she used Ruby's tactic to beat the Boarbatusk is exactly why she should be angry at getting that advice. Regardless of whether she would have done it herself, she'll be judged as having done it just because Ruby told her to. Also, she didn't get upset with Ruby until the repeated talking, where Blake and Yang only said anything once.

She didn't get upset with Ruby for being the leader, she got upset with her for being a bad leader. She never actually said to Ruby that she should be the leader, just that she deserved better than having Ruby for her leader. And up until Ozpin spoke with Ruby, she was absolutely right. Ruby was being a terrible leader, but the talk seems to have fixed that.

Further, even if I'm totally wrong about all this, there's the fact that she was clearly in a bad mood already. The fact of the matter is that in order to snap at Ruby, she needed to be pushed to a breaking point, and Ruby was the one who did that.