Uh, not quite.
Juries are the "triers of facts", not the judge. His-her role is to rule on the law, after a jury has decided on the facts - which in this case the law was utterly and completely ignored.
And if this isn't a text book example of 'judicial activism' I don't know what is. A Federal Judge doesn't like a Federal Law passed by Congress so he ignores it.
Ummm Context is Key.
Juries for the most part dont have a hand in sentencing. Facts, and Circumstances are what a JUDGE is supposed to consider.
Also, Just to go a little further...since we are being overly anal.
The defendant could have waived a Jury trial.