User blog comment:IamThorn/Yang can Kill/@comment-3146930-20140923205112

I don't think so. Obviously one of the triggers for her Semblance is anger or rage, but I don't think it controls her. Out of the 4 team members of RWBY, Yang seems most like the brawler, meaning she probably gets into a lot of fights (she may not start them all mind you). However I doubt she would just straight up murder someone just over a fight.

The red eyes mostly signify that her Semblance is active, but that doesn't mean she is in a completely uncontrollable state like the Hulk. She is still in control for the most part. I mean when fighting the Ursa in the forest, sure she was mad but the moment Blake killed the other Ursa she was back to normal. In the trailer Junior was out of the fight so Yang most likely would have calmed down shortly after regardless of Ruby being there or not.