Towards the end of a three-hour lesson, the post-16 learners asked if they could go early. I said 'don't be bloody silly, I'm having an observation'. That didn't go down well on the score card. However, I did let them out five minutes before the end, partly as a reward for being such darlings, and partly because of form - they have to get somewhere else, and the next class & teacher want to begin on time. I was told I had 'deprived them of five minutes of learning'.