Another one: sometimes, especially in large organizations, there are so many rules that you can't find anyone who actually knows them. Making it unlikely they're being followed.
In large org thinking, if something bad happens, and you add a rule, then it's fixed.
The problem is that this is not compatible with human psychology.
This leads to many rules, the rules are unstructured and impossible to learn, the rules probably also contradict each other.
In my experience, a rule without automatic enforcement should be the absolute last thing to depend on. If you do this, your org is broken.
The Toyota Production System with it's blame on process design instead of humans is still the best way to avoid these issues IMO.
Do 5-whys where human error is not allowed as a root cause. Design your process with poka yoke in mind. If somebody can forget something they will. Don't depend on it.