1miau acted in a fair and correct manner for years
That is correct, he has been a great DT member up to the point when he was debated on a political topic, he decided to do everything at his disposal to punish everyone who disagreed with him, be it the exclusion of a member he trusted for 4 years, removing a positive feedback, or giving a negative feedback.
But here's the simple truth: DT members should not let disagreements affect them when it comes to using the trust system properly--and here I'm making the assumption that the community has reached a consensus on what "proper" use of it is. From what I've read it does seem like 1miau's actions were spurred by emotion, but even if I'm correct I wouldn't say those actions rise to the level of wiping him from the DT list. I don't know where the cutoff point is for iffy behavior and calls for DT exclusion, but in my opinion it didn't reach it in this case.
I agree, I don't think he should be removed from DT just yet, his right-doings still overcome his bad, I just hope that he realizes his mistakes and refrains from doing them again, he needs to control his emotions and act like a grown-up man who can take criticism without the urge of punishing those who disagree with him.