I consider myself to have a great deal of self confidence. And I only speak on subjects that I have done my research on. But I would never interject into another instructors session unless solicitted to do so or it was in my gym. I have observed instructors doing things that I would not approve of or that I thought were dangerous. If it was in my gym, I pulled them into my office. I explained that unless they could show me that the exercise was safe and had a purpose, they were not to continue teaching it in my gym. A few were able to do so. A few were offended, but the responsibility in my gym is mine and I am not going to allow a member to get injured if I can avoid it. If I saw this in someone else’s gym, I would point it out to the owner/manager if I felt someone might get hurt. And leave it up to them to proceed from there.
In forums such as this I will state the facts on a subject if I have done the research to support my position. I won’t do someone else’s research for them, but I will direct them to search topics that can clarify my position if they want to do some work and learn.