When Jimmy left, he wasn't in such a bad mood, although he did feel a bit annoyed.
During his promotion earlier, he was actually prepared for it. After all, a 30-year-old Supervisory Special Agent is quite rare in the tens of thousands in the FBI, especially since he's not the president's son, but a Chinese American, so he's destined not to reach the top. Therefore, he didn't feel too upset at the time.
Moreover, Ruiz fully prepared for him, splitting out a Support Team to let him stay separately, allowing him to be a 'salary thief' without affecting other matters. This way, he could properly take care of pregnant Nia and the newborn thereafter, which was already pretty good.
