Imagine that you are the lawyer for agribusiness giant ConAgra. You are being sued in a complicated antitrust/patent suit and think that the people bringing the suit haven't presented enough evidence for any jury to rule in their favor. You bring a motion saying so before the case goes to the jury, but lose. The 10th Circuit Court of Appeal, whose ruling controls your case, has held in a case right on point that you don't have to make the motion again after the jury rules against you, asking to judge to overrule the jury verdict, to raise the issue on appeal, even though there is a fair reading of the rule that says that you do.
You appeal. The appellate court says that you were right that there wasn't enough evidence for the jury to rule in your favor, that you didn't have to repeat your motion after the jury ruled in accordance with binding precedent, and that you get a new trial in this big dollar case.
Then, the people bringing the lawsuit said that the 10th Circuit case you relied upon was wrong, and that you had to bring your motion a second time after the jury ruled. They win in the U.S. Supreme Court in a 7-2 decision written by Justice Thomas which was released today.
Next time you think that trial lawyers are going through unnecessary motions motivated by needless paranoia, remember this case. (Dissenters Stevens and Kennedy would have given the trial lawyers for ConAgra a break under a variant of the rule that courts are allowed to redress plain error.)