Putting yourself in a situation in which the public might assume you are speaking on behalf of your employer is unwise, unless speaking for your employer is your actual job. And even if it is actually your job, it's just common sense that you shouldn't publish content that makes your employer look bad.

It doesn't matter if you have "permission" or your managers are "aware of it." Permission can be revoked. Managers can change their minds or be overruled.

This is just how the world works. Maybe it's not how things should work, but it's reality. This guy learned that lesson the hard way.