The cases involved in this scenario are under negligence in the law of tort. Law of tort define tort as “an act which causes harm to a determinate person, whether intentionally or not, not being a breach of duty arising out of a personal relation or contract, and which is either contrary to law or an omission of a specific legal duty or a violation of an absolute right”.
On the basis of the above definition, it is established that a tort is a civil wrong independent of contract for which the remedy is common law action for unliquidated damages. Unliquidated damages are those which the court has power to fix, exercisable in its discretion, as distinct from liquidated damages, which is a fixed amount claimed by the plaintiff. 
On the other hand, the tort of negligence has been defined by Judge Alderson in Blyth vs. Birmingham Waterworks Co. of 1856, as “the breach of a duty caused by the omission to do something which a reasonable man, guided upon those considerations which ordinarily regulate the conduct of human affairs, would do, or doing something which a prudent and reasonable man would not do.” According to the judge, actionable negligence consists in the neglect of the use of ordinary care or skill towards a person to whom the defendant owes the duty of observing ordinary care and skill by which neglect the plaintiff has suffered injury to his property or person. 
According to law of tort, in order for one to maintain an action for negligence, the plaintiff must prove that: the defendant owed him a duty of care; there has been a breach of that legal duty and that the plaintiff has suffered injury to his person or property. For this case, it appear that for one to succeed in an action under tort of negligence, the above there ingredients must be there and these are duty, breach and damages. 
Advice to Jason, Penny and Fashions Ltd
Jason who had been drinking heavily at a local public house ought to have taken reasonable care of him while crossing the road. Although he was knocked down by a car that was being driven by Alice, he might not succeed in a case under negligence if Alice argue that the accident would still have occurred without negligence on his part.
As a general rule, the burden of proving negligence normally lies on the party alleging it, but the courts do not insist on the plaintiff to prove where an accident happen which in the normal course of things would not have taken place if the defendant was not negligent. The plaintiff may argue in such a situation that the rule of Res Ipsa Loquitur applies, i.e. things speaks for itself, and then the burden lies on the defendant to rebut the presumption of negligence by showing that the accident might still have occurred without negligence on his part. 
Where the defendant succeeds in proving that he has not been negligent or offers a reasonable explanation of how the accident could have occurred without his negligence, the burden of proof reverts to the plaintiff i.e. he must prove that the defendant was negligent. Before the rule of Res Ipsa Loquitor can be invoked, three condition must be met and they include: that there must be reasonable evidence of negligence on the part of the defendant; that the operation is under the control of the defendant, when the accident took place; and finally, is that the accident is such as in the ordinary course of things does not happen if those who have the duty use proper care.
Even though Jason was crossing the road using pedestrian crossing ought to have taken reasonable care so he could have avoided being knocked by the Alice’s car. But due to the fact that he was already drunk, he was not a conscious man hence he was not mindful of motorist using the busy road. Alice would argue that the accident would still have occurred without negligence on her part since Jason who was run over by her car was already drunk and like any other drunken men, they are never mindful of other users of the road.
A relevant case ruled on res ipsa loquitor concept is that of Bryne vs. Boadle of 1963. In this case, a barrel of flour fell from a warehouse of the defendant on the plaintiff injuring him while walking along the street. The judge held that the plaintiff was not required to show how the accident took place because on the facts negligence could be presumed and the rule of res ipsa loquitor applied. 
Jason on the other hand can bring a case on the newly qualified junior doctor for negligence. A doctor due to his professionalism he is required to exercise his skill and take reasonable care to do the act which he undertakes. The standard of care by which determine whether a person has been negligent or not is the standard of care; expect from an ordinary prudent man in the particular situation.
A prudent man is one who has acquired the skill to do the act which he undertakes. The degree of care, skills or diligence which a man is required to apply varies according to a particular case. Thus when a person has undertaken a duty which requires extraordinary care or skill, he is bound to use great care in order to avoid the foreseeable harm to a person or to his property. On the other hand, if the danger is slight, only a slight amount of care is expected to be used. 
If a person holds himself out as being specially competent or qualified, he is under duty to exhibit such care and skill usually found in persons of his qualifications. For example, one would expect from a surgeon the degree of skill appropriate to a reasonably competent member of his profession.
Similarly, a person treated by a compounder at a village dispensary for his leg wound cannot expect the degree of care of a professional qualified doctor. For this case, Jason expected to be treated professional since he was in a reputable hospital under the care of a qualified doctor. The issue that the complication he developed was a result of combination of alcohol and an antibiotic that was administered by the newly qualified junior doctor is immaterial since the doctor ought to have known the status of the patient before administering the drug.
He ought to have known that the patient was already drunk when he was brought in their hospital. It is also immaterial that the newly qualified doctor is the one who cause the complications since he ought not to have administered the drug without instructions of a well qualified doctor.
When it comes to the issue of the second accident that Jason was involved in when he was being taken to hospital with an ambulance, the accident was inevitable since the accident might have still occurred since in emergency cases, the ambulance usually drive at high spend. The rule of res ipsa loquitur will apply in this issue since the accident would still have happened without negligent on the ambulance driver. In normal circumstance when an ambulance are being driven, they are driven at a high spend in order to save the life of the sick person. 
Joyce, the ambulance driver ought to have taken reasonable care while driving on the road not to injury anyone on the road or any property. Joyce had the duty of care not to cause any damage to any property that may be near the road due to her negligence. According to Lord Escher, “if anyone is near to another or is near to the property of another, a duty of care lies upon him not to do that which may cause a personal injury to that other or may injure his property.” One ought to take reasonable care to avoid acts or omissions which you can reasonably foresee that would likely to injure a neighbour. For this case, the neighbour was Penny and Fancy Fashions Ltd. 
A relevant case studied in the concept of duty of care is that of Donoghue vs. Stevenson of 1932. “In this case, a man bought a bottle of ginger-beer from a retail shop for his girlfriend. The manufacturer had bottled the substance in opaque bottles, so that its contents could not be seen. When the girl poured the content in the glass, it contained the decomposed remains of a snail. The girl was ill in consequence and sued the manufacturer for damage in tort. It was held that the defendant was liable as he owed her duty of care to ensure that the bottle should not contain objectionable matter as it did.” 
Similarly, Joyce owned duty of care to Jason, Penny and Fancy Fashions Ltd. to ensure he drives the ambulance with reasonable to avoid an accident. If Joyce had exercised a duty of care and ensured that she drove the ambulance keenly, the accident would not have happened, hence, Penny would not have been injured and the Fancy Fashions Ltd. property would not have been destroyed.
On the other hand, on the case that when Penny was admitted to the casualty department for injuries and a nurse administered an anti tetanus injection which resulted to Penny suffering brain damage, the nurse was negligent. The nurse ought to have exercise standard of care by which it determine whether a person has been negligent or not expect from an ordinary prudent man in a particular situation. Being a professional nurse, he ought to have exercised extraordinary care of skill and avoid foreseeable harm to the patient. The nurse ought to have gathered adequate history of the Penny (patient) before he administered any treatment.
Although the rule of res ipsa loquitur would still apply in this issue where the nurse would argue that the incident would still have happened without her negligence. During emergency case like of an accident, the injured people are attended to immediately to save their lives. In most case, some patients are usually unconscious and it is not possible to ask them their medical history however, this should not be an excuse for the nurses to be negligent in their work and use this to escape their misconduct in their duty of work.
For Penny to succeed in the case against the nurse for negligent, she must prove that the incident would have been avoided if the nurse had taken adequate proper care in her duty; that the incident was under the control of the nurse when it took place; and that show reasonable evidence of negligence on the part of the defendant. 
In dealing with the tort of negligence, we are not concerned with the breach of our moral obligations; their breach does not create any enforceable right in favour of a person who has suffered damage. For example, failing to render any assistance to a person drowning in a river; but failing to exercise a reasonable standard of care, which may result in injury to a person in injury to a person or to his property, is an actionable wrong. Jason, Penny and Fancy Fashions Ltd. should take charge and sue the concerned parties for damages in tort of negligence.
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Kronman, A.T (1985); Tort Law and the State of Nature, Journal of Law, Economics, & Organization, Vol. 1, No. 1 (spring, 1985), pp. 5-32
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 Penrose, R (2005): Road to Reality: A Complete Guide to the Laws of the Universe, London, Longman Publisher  Jertz, A., Miller L. R, (2004): Fundamentals of Business Law, 3rd Edition, London, Macmillan Publisher
 Penrose, R (2005): Road to Reality: A Complete Guide to the Laws of the Universe, London, Longman Publisher  Jertz, A., Miller L. R, (2004): Fundamentals of Business Law, 3rd Edition, London, Macmillan Publisher  Emanuel, S. L. (2004): Fundamental of Business Law, 4th Edn, London, Educational Publisher  Penrose, R (2005): Road to Reality: A Complete Guide to the Laws of the Universe, London, Longman Publisher  Jertz, A., Miller L. R, (2004): Fundamentals of Business Law, 3rd Edition, London, Macmillan Publisher  Emerson R. W (2003): Business Law, 5th Edn, London, Educational Publisher
 Jertz, A., Miller L. R, (2004): Fundamentals of Business Law, 3rd Edition, London, Macmillan Publisher
 Emanuel, S. L. (2004): Fundamental of Business Law, 4th Edn, London, Educational Publisher