In Kerby v. Abilene Christian Coll., 503 S.W.2d 526 (Tex. 1973), the plaintiff driver suffered injuries when the defendant's school bus ran a red light and struck him. 503 S.W.2d at 527. The plaintiff, driving a linen van, was thrown from his van through its open sliding door when it was struck. Id. The van landed on him, and he suffered injuries. Id. At trial, the court submitted questions to the jury inquiring of the plaintiff's potential contributory negligence in leaving his van door open. Id. The jury answered affirmatively, finding the plaintiff thirty-five percent negligent in causing the accident. Id. The trial court entered judgment in the plaintiff's favor on the jury's verdict but reduced the amount of damages it found by the percentage of negligence attributable to the plaintiff. Id. The appeals court reversed the trial court's judgment and rendered judgment solely in favor of the defendant, concluding that the special issues inquiring of plaintiff's negligence in leaving the van door open constituted findings of contributory negligence and proximate cause, requiring a complete defense verdict. Id. The supreme court reversed both the trial court's judgment and the court of appeals's judgment and rendered judgment for the plaintiff for the entire amount of damages assessed by the jury, unreduced by the percentage of negligence it attributed to the plaintiff. Id. at 529. The supreme court held, "Even if there were proof that the particular injury suffered would not have been suffered had Kerby avoided being thrown from his truck, it would not support the jury's finding of percentage contribution." Id. The court noted, "Negligence which merely increases or adds to the extent of the loss or injury occasioned by another's negligence is not such contributory negligence as would defeat recovery." Id. at 526. Thus, the supreme court held that the trial court erroneously included an issue on the plaintiff's alleged contributory negligence instead of a mitigation instruction. Id. at 528.