Teaching is darn hard. If you had a comment to make, it would have been better to have done it privately. Complaining is just not something that professional teachers do. Part of the problem, we know, is that beginning teachers are not given a crash course in politics. There are politics in any business.
Education is no exception.
Politics aren't necessarity bad. Where I work as a BTSA consultant, we do a workshop on this topic. We find new teachers often shoot themselves in the foot first thing as both of you found out. These kinds of faux pas will get you in more trouble than almost anything else. You have to know the rules and play by them.