[EricH]

While it's generally a good idea to have a mentor doing the email, if you're going to give someone--anyone--the responsibility, and they do their job well (key item here, I'm assuming that there were no issues), then to immediately "direct" them to hand the job over to someone else is tantamount to an insult. I'd also bring this up to the new head mentor--if he doesn't mind your doing it, then the previous head mentor needs to back off.

I also think that someone (and in this case, definitely not a student, though maybe a group of students could be involved as observers/witnesses--this is best handled mentor-to-mentor or parent-to-mentor) may need to have a little chat with the previous head mentor on the following topic: "he could not ship as assistant where he had once been skipper" (to quote Robert Heinlein's Starman Jones). Some people can gracefully resign to a lesser position in the same group; others cannot. Because there is no sure way of knowing, it's generally acknowledged that it's a really bad idea to assign someone who was once high in a group to lower in the same group, even if they volunteer.