I found this strange thing which is IMHO a bug:
The problem is that egreg zapped the question using his golden xetex badge. However, the question isn't tagged xetex, it had the tag but lost it before egreg voted on it. Sure egreg could zap the question anyways using his golden symbols badge.
The question is, whether the system used the correct golden badge and displayed the wrong one, or used the wrong one directly. Or is it status-bydesign that the original tags are considered when zapping the question by the golden badge hammer?