Perhaps, you got in trouble cuz you emailed others?
Since the issue was with the audiologist, you should have only emailed the audiologist... not everyone else as well?
For professional reasons, issues should be made directly to the person involved... not others.
For instance, I'm working at an office. A co-worker does something that I don't like. So, I will email that co-worker directly. I don't send email to that co-worker AND other co-workers in my department AND other employees in the company AND my manager AND etc... etc.
If that co-worker refuses to cooperate with me, then I follow the chain of command by contacting that co-worker's supervisor. I don't contact that co-worker's supervisor AND other supervisors AND other bosses.
This is probably what happened. Since you contacted everyone regarding this issue, you got everyone involved when it actually started with the problem with only one person. (As I mentioned above, it's better to contact just the person directly involved, not everyone else.)
After that problem is resolved, then you can make a neutral comment towards your class on your own time without bringing up the audiologist issue. 
