There were some older guys in my black powder club that didn't wear ear protection. Some wore prescription eye glasses because they needed them, but I couldn't understand why they didn't wear hearing protection and no one stopped them from shooting.
Under some circumstances a minor child should definitely be protected or kept off the range.
In the absence of range rules then a "duly appointed and authorized" range officer may be able to be the dictator. That's why shooting clubs have head safety and range officers and stated range rules that can lead to members being disciplined if the written rules are broken.
But in this day and age there are still some libertarians than would advocate that people have certain rights to engage in risky behavior.
How can a range officer become a rogue authority in spite of the written rules?
I don't think that folks should go without wearing eyes ears at the range, but like our freedom of religion which gives adults the right to refuse necessary medical treatment, I don't see how people's rights can be invaded if the property owner/owners chose not to.
Having a range officer certification doesn't necesarily give them the legal right to supercede the right of the private property owner of the range.
A state law might and there's always the risk of injury laws regarding minor children that may apply.
That's why I mention that the welfare of children might be an exception, or maybe the range officer could make a report to the legal authorities.
Try looking at the situation as if one were a police officer that was called to the scene based on a complaint.
If an adult gun club member were refused the right to enjoy the property because of a rogue range officer, then maybe a trespassing, disorderly conduct or a breech of peace charge could be filed against one party or the other based on who is in the right or wrong.
Theoretically if a range officer exceeded his authority, based on his actions he could potentially end up being charged for attempting to interfere with a member's legal use of range property.
The same would apply to the member if he disregarded a written range rule which the range officer was empowered by the owner to enforce. That's why written range rules are often posted.
If there's a dispute and the police are called, who is legally in the right or wrong?
I don't know, but I think that personal and property rights need to be respected above all, and the courts act as the legal balance between them.
What's the legal obligation of the range officer vs. their legal right to take unilateral action?
Again, I don't know.
All I know is that some of the old guys at my muzzle loading club chose not to wear any ear protection and they were well respected by all of the members.
What could or should a range officer do about it?
Even a child shooting a .22LR rifle outdoors without eyes and ears probably isn't very risky at all.
So when assessing the degree of risk involved every situation is different.