Apportionment of Damages
When concurrent tortfeasors cause an indivisible injury, each has several liability and therefore can be held liable for the whole injury.
When successive tortfeasors in unrelated incidents cause an indivisible injury, the first tortfeasor cannot be held liable for the actions of the second tortfeasor, as he is a superseding intervening cause. However, the second tortfeasor can be held liable for the entire injury.
A jury can compare liability between a tortfeasor and a product manufacturer.