The plaintiff must normally prove on a balance of probabilities that D's conduct fell short of the standard of care required. The mere fact that P has suffered injury or loss through D's act is not enough.
Easson v LNER (1944) KB 421, CA
A child fell from a moving train. The Court said the principle of res ipsa loquitur (below) was not applicable, since the carriage door could have been left open by a passenger and so was not under the sole control of the railway company.
Snelling v Whitehead (1975) Times 31/7/75, HL
A 7-year-old boy P riding his bicycle on a minor road towards a crossroads was seriously injured in a collision with a car driven by D along the major road. Reluctantly rejecting P's claim for compensation, the House of Lords said there was no proof that the driver had been negligent, and in the absence of such proof the claim must fail. [Such proof is generally quite easy to come by - a WHO study in 1962 suggested that even a good driver makes a mistake every two miles on average.] Lord Wilberforce suggested this was a case where no-fault compensation would be appropriate, but that was a matter for Parliament.
Carter v Sheath  RTR 12, Times 10/8/89, CA
P was 13, and late one November evening he was on his way home from a Scout meeting with three friends. They reached a pelican crossing; P crossed (without injury) against the red light, but his friends waited for the green. A short time later, P was struck by a car driven (at a proper speed) by D, who said he had seen the other three boys but not P. P suffered severe brain damage, and could not give evidence. The evidence of the other boys was that they had seen P standing on the barrier at the far side of the road, but had not seen the collision; no one was able to explain what had happened. The Court said that the mere fact that D had not seen P before the collision was not in itself proof of negligence, and that something more would be required to discharge the burden of proof and establish liability.
However, a rebuttable presumption of negligence is created in a number of cases by the principle of res ipsa loquitur, which applies when (i) the thing causing the damage is under D's sole control, and (ii) the accident is such as would not ordinarily happen where those in control use proper care. The onus is then on D to show on a balance of probabilities that he was not careless, and that the accident happened in some other way.
Byrne v Boadle (1863) 159 ER 299, Exch
P was passing DD's premises when he was struck by a barrel of flour falling from above. Affirming the ruling of the trial judge, Pollock CB applied the res ipsa loquitur principle: since barrels do not normally fall from the sky without negligence, and this barrel was under the control of DD or their servants, negligence could be presumed and DD had the burden of proving otherwise.
Mahon v Osborne  1 All ER 535, CA
A patient died shortly after an abdominal operation and post-mortem examination found a swab in his body. The Court of Appeal said negligence had been established, but the majority said res ipsa loquitur applied only to things within common experience, and that was not the case with complex surgical procedures.
Cassidy v Ministry of Health  1 All ER 574, CA
P underwent a minor operation on the third and fourth fingers of one hand; after the operation the hand was bandaged and splinted. During the next two weeks P complained of pain in the hand but was given only sedatives; when the bandages were removed, the whole hand was found to be useless. The Court upheld the trial judge's ruling that the onus was on DD to provide an adequate explanation of this occurrence, and that in the absence of any such explanation negligence on the part of some member of the surgical team (all of whom were hospital employees) could be presumed.
Bennett v Chemical Construction  3 All ER 822, CA
A workman was injured by two panels falling from above, but there was no evidence as to why they had fallen. Since panels do not ordinarily fall in the absence of negligence, the onus was on the company to prove some other explanation.
Henderson v Jenkins  3 All ER 756, HL
The brakes on a lorry failed because of a corroded pipe, and a fatal accident resulted. The corrosion was not apparent on visual inspection, and the manufacturers did not recommend its removal for closer checks. DD claimed a latent defect rather than negligence, but the majority in the House of Lords said this defence could not succeed unless DD brought evidence of the vehicle's history to show that it had not been subjected to any unusual circumstances that might have warranted special inspections. Res ipsa loquitur applied and the onus was on DD to rebut the presumption of negligence.
Widdowson v Newgate Meat (1997) Times 4/12/97, CA
A man P walking along the side of a quiet dual carriageway late one night was struck by a van and injured. In an action for negligence against the van's owners DD, P claimed the driver had been negligent but (because he suffered from a mental disorder unconnected with the accident, making him unreliable as a witness) was not called to give evidence. DD submitted there was no case to answer and called no evidence either. The judge found P had not shown that the accident was more likely than not caused by the driver's negligence, and dismissed his claim, but the Court of Appeal allowed P's appeal. Brooke LJ said the maxim res ipsa loquitur is not commonly applied to road accidents, but on the limited evidence available P was entitled to assert that the probable cause of the accident was the driver's failure to keep a proper lookout and DD had not put forward any plausible alternative explanation. P's claim should succeed subject to a 50 per cent deduction for contributory negligence.
Fryer v Pearson (2000) Times 4/4/00, CA
A gas fitter C working at DD's home knelt on the floor and was stabbed in the knee by a sewing needle hidden in the deep pile carpet; the needle broke in C's knee and caused permanent disability. His claim failed: Waller LJ said negligence would be established if the only proper inference was that DD had known the needle was in the carpet and had allowed it to remain there; on the facts no such inference could be drawn and this was merely an unfortunate accident. (Obiter, May LJ deprecated the use of Latin phrases such as res ipsa loquitur, that are not readily comprehensible to those for whose benefit they are supposed to exist.)