Mrs Paul underwent a scan to determine whether she had a berry aneurysm in 2003, which her radiologist, Dr Cooke failed to diagnose at the time. In 2006, Mrs Paul underwent a further scan in which the aneurysm was detected.

Following her diagnosis, Mrs Paul underwent removal of the aneurysm in 2006 during the course of which the aneurysm ruptured, causing her to suffer a stroke. Dr Cooke had no involvement in that surgery.

Mrs Paul subsequently brought proceedings against Dr Cooke alleging that he was negligent in failing to diagnose the aneurysm in 2003, holding him responsible for the stroke.

Based on the evidence that in 2003 a procedure known as clipping was used to remove such aneurysms and that in 2006, a different procedure known as coiling was used, Mrs Paul argued that in the event she had undergone surgery in 2003, she would have avoided the injury.

Clipping involved open brain surgery whereas coiling was a procedure performed through the arteries. Although both procedures carried an approximately equal inherent risk of rupture, there was found to have been an increased risk of stroke in the event of rupture with coiling as there was greater access to minimise damage from the rupture during clipping by virtue of it being an open brain procedure.

Rupture and stroke were an inherent risk in both surgeries and could not be avoided with the exercise of reasonable care and skill.

The Court found that had there been a correct diagnosis in 2003, Mrs Paul would willingly have faced the risk of surgery then.

The evidence indicated that the delayed diagnosis did not itself increase the risks associated with surgery in that Mrs Paul’s aneurysm did not change in size, shape or propensity to rupture during those three years.

The Court concluded that Mrs Paul’s condition pre-dated Dr Cooke’s diagnosis and the relevant risk – the risk of surgery only arose after the aneurysm had been diagnosed. Although Dr Cooke had breached his duty to Mrs Paul by failing to diagnose her in 2003, this failure did not cause the stroke Mrs Cooke suffered during her surgery. Dr Cooke did not create the relevant risk and the risk could never materialise until Ms Paul chose to undergo surgery.

Dr Cooke was not held liable for the harm suffered by Mrs Paul despite his failure to diagnose as there was no causal connection.