This is as much Hiroshi's fault as it is Umatarou's. He's the one who made her stronger than Six, and had her focus mostly on combat training.
As a result, she got far more power than she can responsibly handle.
@rc1138
? Not only are they scientists, they're barely even adults. Hiroshi's like 21 or something and I'm pretty sure Umatarou's still a teenager because he skipped 5 grades. Another college student, a high schooler, and a robot only slightly older than you aren't much better.
Umatarou is the one with the ridiculous "romanticism" but it is Hiroshi's specialization and responsibility to deal with AI education and development, and when they are trying to advance consciousness he more than anyone should know that a "person" can be as gentle as they can be cruel.