Possible Clues:

• Instructed in pronunciation of tense
• Gave instruction
• Reported to be stretched tight, as instructed
• Sound far from relaxed, being disciplined
• After conclusion of whodunnit, anything explained?
• Did school put rubbish outside that's foul?
• Was a teacher
• Worked as an educator
• Was head of the class?
• Stretched, one hears, getting disciplined