can slaughter an entire village full of human beings, but he can't use a recess appointment because no one knows exactly what a "recess" is.
Yoo's steel trap of a legal mind runs afoul of the definition of a recess. If the Constitution does not specify what a recess is, the President can make a recess appointment when they are not in session. When they are not in session, they are in a recess. The "three day rule" is nonsense. Yoo is simply pissed off that he didn't tell George W. Bush to do exactly this back in the day.