Yeah that's incredibly suspicious. Weiss could do a lot of consideration and deduction and try to figure out why someone would be acting like this in a situation like this, or try to quietly pursue him to satisfy her curiosity.

She could do that, but her temper is as short as the rest of her, and she's not exactly thinking straight at the moment.

"Oh you do, huh? Care to explain why you're running so fast from that?" she demands, gesturing up at the banner.