First of all, the case US v Microsoft was originally a 1998 case, not 2001. Jackson entered his judgment in June 2000. Microsoft appealed timely. It went from Jackson's district court, straight to the Supreme Court, using 15 U.S.C. §29(b), and the Supreme court issued 530 US 1301. While the states filed for being heard, the Supreme Court declined them, remanding the whole case back to the lower courts.
In No. 00-139, direct appeal [to the Supreme Court] is denied, and case is remanded to the United States Court of Appeals for the District of Columbia Circuit. The Clerk is directed to issue the judgment forthwith. In No. 00-261 [the request of the states to be heard], certiorari before judgment is denied.
The case thus went to the DC Circuit Court of Appeals, and due to the time it takes to schedule, became a 2000 case. The court noticed, that while Jackson was still on the case he had given interviews about it:
The Court of
Appeals held that: [...] (6) district judge’s
comments to the press while the case was
pending required his disqualification on
Immediately after the District Judge
entered final judgment on June 7, 2000,
accounts of interviews with him began appearing in the press. Some of the interviews were held after he entered final
the District Judge’s disqualification under
§ 455(a): a judge ‘‘shall disqualify himself
in any proceeding in which his impartiality
might reasonably be questioned.’’
28 U.S.C. § 455(a). The standard for disqualification under § 455(a) is an objective
one. The question is whether a reasonable
and informed observer would question the
judge’s impartiality. (p.114)
Our application of Liljeberg leads us to
conclude that the appropriate remedy for
the violations of § 455(a) is disqualification
of the District Judge retroactive only to
the date he entered the order breaking up
Microsoft. We therefore will vacate that
order in its entirety and remand this case
to a different District Judge, but will not
set aside the existing Findings of Fact or
Conclusions of Law (except insofar as specific findings are clearly erroneous or legal
conclusions are incorrect). (p.116)
When Jackson gave the interviews, he violated the Code of Conduct for judges because the appeals process was not yet complete and he was still on the case. As such, he created the image, that he might not be impartial:
Canon 3A(6). The admonition against public comment about the merits of a pending or impending matter continues until the appellate process is complete. If the public comment involves a case from the judge’s own court, the judge should take particular care so that the comment does not denigrate public confidence in the judiciary’s integrity and impartiality, which would violate Canon 2A. A judge may comment publicly on proceedings in which the judge is a litigant in a personal capacity, but not on mandamus proceedings when the judge is a litigant in an official capacity (but the judge may respond in accordance with Fed. R. App. P. 21(b)).
Jackson did not appear as he was to be heard in the Circuit Court. As shown above, the DC Circuit Court of Appeals found, he did violate the code of conduct and disqualified him under 28 U.S.C. § 455(a). While this did suffice to overturn the verdict prescribed by Jackson, the court did not throw out the findings of fact that had been issued well before the interviews and noted that the traditional setup might be inadequate for this case. They remanded back to a different judge to decide a remedy under a different scope.
The case didn't end there, Microsoft attempted to get even the findings of fact thrown out based on the very ruling that sent it back for remand, claiming that the judge had shown to be biased way earlier, during the trial and before the finding of facts. They did so by appealing a second time to the Supreme Court in August 2001 but the court rejected to hear the case in October.
In the end, DoJ and Microsoft settled in November 2001, the settlement was accepted by the District Court in 2002, and affirmed by the appeals court in 2004, as some states didn't want that one.