Driving

Hi, I had sickness and diarreoa from 4am and let my driving instructor know that I was unwell and it my blood sugars are very unstable due to it at 9am since I had a lesson at 6pm. I was pretty upset with the response I got as I feel even though I explained my sugars were unstable I was expected to still come out to drive or face a charge. The response was-
Sadly I will need to charge you for it so if you change your mind let me know and I will come and get you.

Are driving instructors taught of the dangers of having hypos on the road?