Your take on how the Liberals have failed to follow the SCC decision on physician-assisted death is absolutely right.

I just want to point out that your statement on 'a law's normal course' is mistaken ("A law's normal course is that Parliament enacts the legislation, and then if necessary the Supreme Court identifies any subtleties that might need amending.")

There is no such process.

The Supreme Court only gets involved in a small fraction of cases which individual parties have pursued through a trial and appeal.  It's expensive for them, lengthy, and far from normal.  If the Supreme Court does decide to take on such a case, it does not then 'identify any subtleties that need amending.'  

If it finds that certain sections of legislation violated the Charter, it declares those sections to be constitutionally invalid.  In some cases, it has allowed a 'grace period', to allow the government to amend it, as it did in the Carter decision.