As usual the Netherlands has come up with a complex law that is so complicated it seems simple.
Euthanasia (assisting in suicide) is a crime. This means that everyone who does has to report it to the authorities. However if proper care has been taken (the person performing is a doctor or relative who got doctor's permission, the person was capable of expressing their will in clear mind) the case will not be proscuted and no criminal record kept.
If not executed correctly, a punishment for manslaughter/murder can be given. Unfortunately punishment for that is 200 hours community service...
Medical staff does not have the option of euthanasia if the patient is past the point of being clear of mind, even if it is clear the patient is terminally ill. They hover do have the option of withdrawal of service, giving no other medication as pain killers and advising the patient not to eat or drink (patients have the right to refuse food and drink). Usually with terminally ill that causes natural death in a couple of days.