Yujiro doesn't care about the oath, he just wants to get it over with, he doesn't have the same ego he used to so he just says fuck it and leaves
More importantly Itagaki clearly dislikes Trump a lot, please don't try to imply he think trump won or something lol
This clears up a lot about why they were so forward, they thought that Saitou cut herself for attention and that Yokoi didn't understand the situation. From their perspective it was extremely urgent to have a talk with them. Also explains over-sharing