General Discussion

The Law in Lawful Order is determined by:
1. Active Federal Code and Regulations in regards to the Military in Particular, then
2. The UCMJ, then,
3. Active Codes and Regulation for Federal Service actions (Contracts, Legal Actions, ect...)
4. Active Laws, Directions, Treaties, Code, and Regulations as directed by Congress, and finally
5. Verbal Orders from the Officers above the Military Member and Commander in Chief that fall under the 4 sections above.

That's why a Unit Commander also gets in trouble if they even just suggested they were ordering an action that caused an incident causing environmental damage - or the unwarranted death of a civilian or service member. And responsibility goes up the chain of command.
Commanding Officers have lost their command for "Lack of Confidence' because they ignored a pompous knucklehead Senior Enlisted, Officer, or Civilian Manager under their command.
Anything that can end up with an incident investigation can become the result of an Unlawful Order.
If you're an Officer, or even a Senior Enlisted Leader, it Behooves You to know the pertinent Official Laws, Regulations, and Restrictions that impact your Mission so you are not responsible for giving or following an Unlawful Order.