12.04 Concurrent Negligence Other Than Defendant's More than one person may be to blame for causing an injury. If you decide that a [the] defendant[s] was [were] negligent and that his [their] negligence was a proximate cause of injury to the plaintiff, it is not a defense that some third person who is not a party to the suit may also have been to blame. [However, if you decide that the sole proximate cause of injury to the plaintiff was the conduct of some person other than the defendant, then your verdict should be for the defendant.]