Some cases are difficult. Some are easy. The nice thing about the hard ones is you never really know if you get it right - that's why it's hard. But messing up the easy ones is a real kick in the pants.
Worse, I guess, if you're a district judge. Worse if you get chastised, hard, by the appellate court.
Take, for instance:
After we have remanded a case with specific instructions, attorneys rarely attempt to have the district court defy our mandate. And even if they try it, a district court is seldom misled into that kind of error by them. This is one of those rare cases where the attorneys representing one side successfully urged the district court to act contrary to our mandate. Of course, we reverse that part of its judgment.
Or:
Needless to say (or maybe not), a district court cannot amend, alter, or refuse to apply an appellate court’s mandate simply because an attorney persuades the court that the decision giving rise to the mandate is wrong, misguided, or unjust. A district court can, of course, wax eloquent about how wrong the appellate court is, but after the waxing wanes the mandate must be followed.
The source of this discord: the definition of "groceries." Winn Dixie says it means "food and household items." The folks Winn Dixie was suing say it means "food." There's a Florida case saying it means the former. The district court used the latter definition. The Eleventh Circuit said "wrong, see this prior Florida case." On remand, the defendants said "you don't have to follow the appellate court because that Florida case came after this contract, so the parties didn't negotiate based on that definition." The district court said "OK." The Eleventh Circuit said "Really, really, no."