[burutthrow1234]

What if the President orders the Vice President to shoot someone in the street?

What if the President signs an Executive Order directing himself to shoot someone in the street?

[_heimdall]

Simply envoking the title of the office doesn't mean the act falls within the lawful powers of the office.

Think of it like the police. An off duty cop is not acting under official powers. Even on duty, a cop is limited in what and how they are supposed to do their job and crossing outside those bounds technically makes them personally liable. I wouldn't begin to say we are any good at actually holding police accountable when they act outside their official duties, but that's a whole separate can of worms.