I responded here.
Jim Schiel may have more to add.
By the way, I would question the title of "ScrumMaster" for anyone who is distributing tasks, committing to work on behalf of his team, etc. The ScrumMaster is a coach serving his team, creating conditions for self organization. Not a taskmaster.
--mj (Scrum Trainer, etc.)
I responded here.
Jim Schiel may have more to add.
By the way, I would question the title of "ScrumMaster" for anyone who is distributing tasks, committing to work on behalf of his team, etc. The ScrumMaster is a coach serving his team, creating conditions for self organization. Not a taskmaster.
--mj (Scrum Trainer, etc.)