This is the first and final appearances of Ruth Westdal and Mike Maguire and Todd Brewer (uncredited) in the series.
Misspellings on the classroom blackboard: It's apparent that "detention" is written on the blackboard; however, only the middle letters "...TENNS..." can be seen.
Alasdair calls the principal "Mr. Smack", and "Mr. Richard Smac" is written on the chalkboard on the side of the room.