In this interview, he complained about people who asked if "the right thing" was done at the end of the movie.
He said the question made him angry because only white people asked it, which, in his pathetic little brain, means that they're valuing white property over black lives.
As if random retaliation against a white person is appropriate whenever a black person dies, whether or not the white person had anything to do with the black person's death.
The film itself doesn't judge it like that though. That's one of the things I appreciated about it, it doesn't moralise.
Not judging the conduct of those characters is only a good thing if reasonable minds could differ as to whether or not what they did was justified. That's not the case, however.
If Spike Lee thinks a case could be made for the notion that it's acceptable to destroy an innocent man's property and livelihood because it would make a mob feel better, then he's obviously not reasonable.