It’s not an air shut case

This wonderful mix up was heard at a training seminar.  The instructor was indicating that discrimination lawsuits are not always straightforward and then proceeded to combine “air-tight case” and “open-and-shut case”, both meaning straightforward situations without complications.  The speaker may also have been thinking of air lock doors that seal out air completely, found in airplane exit doors.  This is a great example of a congruent conflation, mixing two closely defined phrases.  A big shout out to Bill Shaffer for sending this one in to Malaphor HQ!