WA driver may have had pre-crash seizure

A Perth man who drove on after fatally hitting a motorcyclist may have had an epileptic seizure before the accident, a court has heard.

Michael Robert Donovan has pleaded guilty to charges including dangerous driving causing death over the incident on January 7 last year, which claimed the life of 34-year-old Jonathon Charles Murphy.

A woman whose car Mr Murphy's motorcycle was shunted into, also sustained injuries in the Mitchell Freeway smash.

The District Court of Western Australia was told on Friday three neurologists had all agreed Donovan suffered from a vascular condition known as arteriovenous malformation and may have suffered a seizure before the crash.

If so, that would be consistent with his claim that he had no memory of it, the court heard.

Judge John Staude questioned defence lawyer Frances Veltman and prosecutor David Jubb, asking why a guilty plea had been entered and why the state had accepted evidence that was exculpatory.

"All I can say ... is he admits he was the person who was driving and he's terribly sorry," Ms Veltman said.

Judge Staude replied: "It's not good enough. I find this whole matter very disturbing."

He reserved his decision on whether or not the court should recall the pleas and convictions, and enter a plea of not guilty, meaning a trial could be held.

Both parties have 28 days to deliver submissions ahead of Donovan's next court appearance on July 22.

His bail has been renewed.