Mike Brown's early season firing may have been surprising, but it wasn't all that controversial. Yes, the firing happened early in the season, but few people really took up the "Save Mike Brown!" cause.
However, the NBA's history is littered with controversial coaching moves mid-season that do bring out skeptical and often harsh rebukes from fans, media and even players. You'll notice that most of these controversies have been fairly recent. This isn't because of a harbored bias toward these recent events. Instead this speaks to a realization that prior to the mid-1990s, NBA teams rarely fired a coach during the season who was winning games.
So without further ado here are the controversial occasions when NBA teams switched horses in the middle of a stream. Giddy up!
(as always a hearty thanks to basketball-reference for their statistical help)