In a vaguely related matter I was taught at school by various wildly unqualified individuals (and a few who were actually qualified). Once the woman teaching me biology pronounced 'denatured' 'den-attured' when I said this word in front of my dad (who was a biology teacher) he corrected me and explained why 'de-natured' was obviously the right pronunciation. I took this back to the teacher with glee and corrected her during a class, despite being obviously right and giving the explanation for why I was right, she refused to correct herself in front of the class and proceeded to use the errant pronunciation for as long as I was taught by her.
In a vaguely related matter I was taught at school by various wildly unqualified individuals (and a few who were actually qualified). Once the woman teaching me biology pronounced 'denatured' 'den-attured' when I said this word in front of my dad (who was a biology teacher) he corrected me and explained why 'de-natured' was obviously the right pronunciation. I took this back to the teacher with glee and corrected her during a class, despite being obviously right and giving the explanation for why I was right, she refused to correct herself in front of the class and proceeded to use the errant pronunciation for as long as I was taught by her.