Both share blame, guilt, fault and culpability in the creation of wrongs, harm, immorality and evil
Of course they both must share the blame. The one who orders the bad thing is triggering the actions that will result in something bad happening, and the one following the order is choosing to follow it.
One debatable question would be: if the person following the orders must either follow the order or be killed himself... in this case should the person be put to blame as well? when he was simply trying to save his life?
An immoral act is an immoral act, regardless of justification such as personal survival. The action and what it does to another is what matters. Kill the baby or I kill you and the baby. You can choose. One is an immoral choice on your part that carries blame. The other is not an immoral choice where you can't be blamed for something you didn't do.