"All becuase the stupid person who booked them, didn't take time to check them out, before they booked them and ensure they were suatble for what they wanted"
Is one way of looking at it and I wouldn't argue that the headteacher should have thought it through.
However, for me (as you can probably gather) it raises bigger questions of the acceptability of "blacking up" in this day and age. The mixed evidence around the history of the "tradition" makes it an even harder job to justify the practice.