What I found (best described as) annoying was that she repeated the same mistake
again that could have cost her comrade's life. You'd think such an emotionally stimulating event would have a greater impact on her, but she still jumped the gun. It's almost like she's forgotten her lesson.
Kudos to Uiharu for yelling at her. Not telling anyone about it would have just mean Kuroko will repeat the same mistake without thought. If she didn't talk back, it would have been the second annoying thing for me.