This is why teacher tenure is necessary.
So we're left with tenure as an imperfect but practical way to limit the damage that can be done by bad administrators and crazed parents. Which is why tenure is important.
Right or wrong, this teacher will be tainted and have his or her career ruined, over the use of a book in the classroom. Ender's Game is a book that has been widely used in high schools for at least 15 years.
Teacher tenure has problems and LIFO (way worse) has a ton of problems but I wouldn't hold your breath waiting for better small-town politics.