ActionComplete / ActionFailed called after Action completion

The worker now calls ActionComplete or ActionFailed on state, depending
on the success state of the Action and any errors.

The hook is set to an error state if the Action hook is missing, or if
other errors take place during hook execution.  If the Action hook sets
a fail state, the Hook will not error, rather the Action will fail.
At this point the hook as executed, but we failed to record that fact in the database for whatever reason. Is it safe to re-execute a hook, possibly many times if the state has shat itself ?