Yes, you are right. You are insightful. Things like that, such as a teacher with incorrect pronunciation can happen. However there are so many tools to use today.  What is interesting is that some customers have pointed out about the mistaken pronunciation but that teacher decided to take the advice for granted instead of improving himself. A teacher must have skill and also the humility to admit that he or she has things to learn. 

I have been involved with the English language for a couple decades and I believe I can learn a little bit everyday. Just the other day I learned about Zero Conditional, something that we use in English but we are not aware ( as in conditional clauses where present matches with future or vice-versa when we combine two independent sentences/clauses together). There are things to learn every day. This forum does help a great deal in that learning process. 

Thanks to all of you involved here.