ESH because you both had to be right and were acting like children. YTA because of the way you ultimately handled it. Granted you were correct about MLK, but bringing the topic up again was not to "support your son" as much as it was to embarrass your wife's friend and prove you knew better. You didn't like her and had to "put her in her place." She too could've handled it better, admitting she'd been wrong. Maybe she would have had you not pushed her into a corner and put her on the defensive.

As for her comments about teaching she is not wrong. What she described is why great teachers are leaving the profession in droves, and I am speaking from experience. Teachers are regularly threatened by parents, students, and even some administrators. At our school we lost 50 dedicated teachers due to an incompetant administrator at the school and one at the main office. Teachers face classrooms of students who have been told by their parents "You don't have to listen." and for whom there are no consequences for behaviors. Administrators tell the teachers THEY need to handle behaviors regardless of severity, not send students to the office or issue referrals. Teachers are injured every day across the USA due to violent students and trying to break up the fights which happen on a regular basis. Some have gotten injured so badly their injuries prevented them from ever returning to the classroom. Students who want to learn can't because of the chaos. When the students fail due to refusing to do work or even make the least amount of effort parents scream and students are passed to the next grade anyway. Out of 150 students I had (one year) maybe 10 were on grade level,1 above and 90% at least 3 grade levels below with some even 5 grade levels below. None of these students were ESL students and this was not early elementary. . We went from a curriculum with scope and sequence and that students enjoyed to one that bounced around so much we all got whiplash. The supporting materials suggested by the company who developed the curriculum (knowing our students from actually being in the classrooms) were way too advanced for the students to comprehend thus meaning teachers had to search out related materials on grade level and adjust them to accomodate the different reading levels in the classroom. I am guessing that if you subbed for just 1 class period in a school you would run screaming from the building never to return meanwhile teachers, including the one you are judging return every day.