In what circumstances will a court grant a motion for a new trial after a jury found that a truck driver was negligent but not a substantial factor in causing a collision?

In David v. Hernandez (2014) 226 Cal.App.4th 578, a trial court abused its discretion when it denied a motion for new trial after a jury found that a truck driver was negligent, but did not cause a collision. In denying the motion, the trial court found that the defendant parked his truck in violation of a statute and that the truck would not have been in the appellant's path "'"'but for its having entered from the right, a position in which it had no legal right to be.'"'" (Id. at p. 589.) Given those findings, the evidence was insufficient to support a finding that the truck driver's negligence was not a substantial factor in causing the collision. (Id. at p. 592.) Fortunately here, the trial court recognized the same problem and granted appropriate relief to the Duran family.