Mansfield v Weetabix [1998]
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Mansfield v Weetabix [1998] 1 WLR 1263 is an English tort law case concerning the standard of care expected of a reasonable person with a particular mental condition at the time of the negligent act.
Tarleton, an employee of Weetabix, was unaware that he had a condition causing his brain to malfunction when his blood sugar was low. Tarleton drove while hypoglycemic, leading to a series of accidents. He was found liable at trial, and he appealed the decision.
The key issue was whether the defendant was required to achieve the standard of a reasonable unimpaired driver at the time of the accident or whether the reasonable person should be imputed with the defendant's condition.
The Court of Appeal allowed the appeal under the altered standard of care by which the defendant was not in breach. Leggatt LJ emphasised that the standard of care should be that expected of a reasonably competent person unaware of their impairment. Aldous LJ stated that the standard of care for the defendant was that expected of a reasonably competent driver, considering that he did not know and could not reasonably have known about his condition.
The new standard of care, as prescribed by Legatt LJ, implies that when the defendant is unaware of their mental impairment, the standard of care shifts to consider the mental illness. This allows for leeway, recognising that no reasonable person can be expected to mitigate an unknown impairment.
This case appears to contradict Dunnage v Randall [2015], where it was decided that mental illness should not be considered in determining the standard of care. Arden LJ in Dunnage distinguished Mansfield, but there is a criticism that she misunderstood the key issue in Mansfield. The focus in Mansfield was on whether the standard of care should impute the defendant's condition or not, not on fault prior to becoming disabled.
In summary, Mansfield v Weetabix establishes a principle that, when the defendant is unaware of their mental impairment, the standard of care should consider the specific mental condition. However, it seems to be in apparent contradiction with Dunnage v Randall, with critiques focusing on the interpretation of Mansfield's key issue.
Tarleton, an employee of Weetabix, was unaware that he had a condition causing his brain to malfunction when his blood sugar was low. Tarleton drove while hypoglycemic, leading to a series of accidents. He was found liable at trial, and he appealed the decision.
The key issue was whether the defendant was required to achieve the standard of a reasonable unimpaired driver at the time of the accident or whether the reasonable person should be imputed with the defendant's condition.
The Court of Appeal allowed the appeal under the altered standard of care by which the defendant was not in breach. Leggatt LJ emphasised that the standard of care should be that expected of a reasonably competent person unaware of their impairment. Aldous LJ stated that the standard of care for the defendant was that expected of a reasonably competent driver, considering that he did not know and could not reasonably have known about his condition.
The new standard of care, as prescribed by Legatt LJ, implies that when the defendant is unaware of their mental impairment, the standard of care shifts to consider the mental illness. This allows for leeway, recognising that no reasonable person can be expected to mitigate an unknown impairment.
This case appears to contradict Dunnage v Randall [2015], where it was decided that mental illness should not be considered in determining the standard of care. Arden LJ in Dunnage distinguished Mansfield, but there is a criticism that she misunderstood the key issue in Mansfield. The focus in Mansfield was on whether the standard of care should impute the defendant's condition or not, not on fault prior to becoming disabled.
In summary, Mansfield v Weetabix establishes a principle that, when the defendant is unaware of their mental impairment, the standard of care should consider the specific mental condition. However, it seems to be in apparent contradiction with Dunnage v Randall, with critiques focusing on the interpretation of Mansfield's key issue.
