That kind of thing can happen in any work environment, frankly. Sometimes people end up in the "yes I can do that" status group. Could be they have union repr

That kind of thing can happen in any work environment, frankly. Sometimes people end up in the "yes I can do that" status group. Could be they have union representation and contract rules that give them considerable agency coupled with low cost and risk. Could be they are untouchable for some other reason too, principle friend, family, lover, child, sibling... Or, could be they have secured it through various relationships, power, leverage. Unions do not cause this. Poorly functioning workplaces can permit it to happen, and any workplace, union or not, can be poorly functioning for a ton of reasons, legal, contractual, managerial, financial... Where that agency exists, sometimes people exercise it, simple as that.