I think the problem is ok he might have a mental health problem but with that condition he is capable of murdering his own dad. Obviously he is capable of being a killer and the fact he could potentially be allowed it society if the doctors think he has ticked all the boxes is mind boggeling.People saying that this sentence is unfair clearly don't understand mental health.
It's the biggest issue in Australia and it's only getting worse
No doctor can guarantee someone likes that behaviour.
If your brain is capable of allowing you to perform such atrocities you should be spending the rest of your life locked up.
Not to mention you as a human are guilty on the crime. Regardless of your mental state at the time.