My colleague posted a photograph of all the paperwork he'd been left to do to our work's group chat. He is now in major trouble with our supervisor because the paperwork had confidential information on it.
However, I am wondering how serious this is as you couldn't read anything from the photograph as the papers were stacked and at an angle. So no info was passed on. Also the group chat is for work and was seen only by the staff. Although it is social media, it is encrypted.
Of note, the supervisor was responsible for not completing the paper work the day before which is why perhaps they are so angry. My colleague has been given a formal warning.
How would you respond to this? Is the formal warning appropriate or indicative of unprofessional behavior by the supervisor? (There was another incident with them overreacting to a clarifying question from another colleague recently.)
If it is the latter what is the best way to go about protecting myself?