Yes, there was a legal mistake - the lower court made a mistake of law when it concluded that it had jurisdiction.
This sort of issue happens all the time, particularly in courts of more limited jurisdiction (like the Tax Court) and it arises out of precisely the sort of legal error the appellate system exists to fix.
Get a grip and stop bloviating. You’re beginning to act like a progressive.
A competent judge does not make that kind of 'legal mistake'.
This isn't the only 'legal mistake' a circuit judge has made. Like the Minnesota judge that required Homan to report ICE's activities every day until she was slapped down in very clear terms that it was a major violation of seperation of powers. A competent judge doesn't make that kind of mistake.
Then there was Judge Boasberg himself that demanded that Trump go outslide US jursdiction and bring back deportees that he said were denied due process.
And there is at least one judge that defied the higher courts and tried to force Trump to do his bidding and I think is going for a third run.
And now there's a judge threatening the President with 'consequences' if he doesn't do her bidding.
Let's not forget the two judges that issue opposite rulings on the same case, and somehow both expected to be obeyed.
So please don't tell me that a judge trying to run the Iran war is out of the question. Crossing the lines of separation of powers has been done at least twice, there's little stretch to it happening in this case.
