I actually think that nice is often a sign of the opposite. People that I know that are energetic, elevated levels of nice are the worst. But I also know some that are low grade and chill kind of nice, that are horrible as well.

It's awful that you had to live in the same place for two more years.

I remember watching a video on youtube, I think it was Darren Brown, who speaks about mind control. He gave an example of deescalating a raging man that was trying to fight him on the street in Las Vegas. He quickly asked him a random, unrelated question. The guy immediately unraveled. They ended up sitting on the curb, talking and the guy crying.

Deescalating was a good choice in your case too. Your instinct and remaining calm was what you needed in the moment.