I see that Michael has the Mortarboard badge, but has asked and answered no questions. Is this a bug?
The user also has the Good Answer badge, but when you click through to it, it just says:
(post deleted or otherwise unavailable)
Apparently, this user posted one really good answer that caused him to earn all those badges, but it was later deleted (perhaps along with the question it was posted for). This caused him to lose all the rep gained from that answer, but not the badges, since those are permanent.
That's as far as I'm able to get with my limited rep here. A ♦ mod or a user with 10k+ rep should be able to see the deleted answer and possibly provide further information.
For the sake of completeness, and so everyone who doesn't have enough rep to see deletions might marvel at how such a thing were possible. (I would have added this to Ilmari Karonen's post, but felt it would be presumptuous to do so.)