Causation

Causation

1. test of causation

   • s51WA
     • a) that the negligence was a necessary condition of the occurance of the harm, (factual causation); and
       • the 'but for' test
         • not necessary to be sole cause; strong v woolworths limited t/as big w
           • march v stramare; trucki in middle of road & drunk driver
         • adeels palace; no proog that security would have stoped gunman
         • deficiencies of the 'but for' test
           • where the but for test indicates that the plaintiff's injuries would have been suffered regardless of the neglifence, this will be effective to establish that the negligence was not a cause of the ijuriies
       • inferences in the law
         • causation will fail where the surronding circumstances demonstrate that it was only possible that the breach caysed the harm; lithgow city council v jackson
         • where there is no direct evedice about causation, a court might infer causation on the basis of circumstantial evidence stong v woolworthsr
       • specific illustration of factual causation; the misdiagnoisis/mistreatement cases
         • where P has pre-existing condition which means that they are legally certain to suffer injury, the d will not nbe liable for having negligently failed to diagnose that injury; hotson v east berkshire area health authority
         • Medical; P can not sue for 'loss of chance; chappel v hart
     • b) that it is appropriate for the scope of the negligent person's liability to extend to the harm so caused
       • requires cout to determine that it is ;'appropriate for the scope of the negligent person's liability to extend to the harm'
         • s51(4) states that in answeing this normative Q's the court must consider 'whether or not and why responsibillity for the harm should be imposed on the negligent party
       • novus actus intervenus
         • an intervening act or event has occured which breaks the chain of causation between the D's negligence and the p's injuries
           • either voluntary human action or supervening event ' the conjumction of which with the wrongful act or ommission is by ordinary standards so extreamly unlikely as to be termed a coincidence; haber v walker
         • whether act was reasonably forseeable; march v srareman
       • intervening negligent or intentional action of a third party
         • an intervening act will not amount to novus actus interveniens where the defendent's negligent conduct created the risk of injury form a 3rd party as occurred, and the injury occured 'in the ordinary course of things; mahoney v j krushich
           • if medical treatement so gross it breaks chain only doctor/hospital will be liable, however if the negligent medical treatment does not break the cahin of causation, the defendant will be jointly and severally liable with the doctor/hospital for the exacerbation of the injuries that resulted for the negligent medical treatment
       • intervening malacious action of a third party
         • might not be the 'very risk' created by the Ds conduct; rickards v lothian
           • test; whether D's negligence has created the very risk; dorset yeacht co ltd v home office
       • intervening negligent act of plantiff
         • rarely break chain; march
       • intervening intentional act of P
         • not novus actus unless voluntary; caterson v commisioner for railways
           • and only outside scope of forseeability; medlin v SGIO
       • multiple successive sufficient event
         • you must take your plaintiff as you find them; the second tortfeasor is only liable for the harm they cause 1st tortfeasor still iable for the harm they cause; baker v willoughly
           • baker will not apply; where merely vissidtude of life sibsequent even must be taken into account when assessing the extent of d liability
       • failure to warn of medical risk
         • in addition ot breach patient must further establish a causal link between the breach and the injury suffered. can only be established if p can prove that they would not have gone ahead with procedure if knew of facts; chappel v hart
           • s51(3) WA; if it is relevant to the determination of factual causation to determine what the person who suffered harm (the inured person) would have done if the negligent person had not been negligent, thhe matter is to be determined subjectively in the ight of all relevant circumstance
       • res ipsa loquitar; the thing speaks for itself; 3 conditions must be established ; mummery v irving