This may not fit your comfort level, but why not ask the prof if you can address the class about the incident? Tell them that you understand the responsibility of a PhD student is to be prepared in class and that you didn’t want to let them down, but that you may on occasion need to pop some glucose. You may get some annoying comments or over-solicitous responses. But you will SHOW a few people that diabetes is just something you can and have and will deal with.
I am a 36-year veteran of diabetes. I have glucose tablets stashed everywhere at work. But today, I ignored a dropping blood sugar until I found myself buying some Raisinettes from a vending machine and then had to ask my coworker to open them because I couldn’t grasp the bag. Nice guy that he is, he watched to make sure I popped a few in my mouth. During this all, we carried on a work conversation like nothin’ was happening. That’s the way I like it.
There are lots of other temporary distractions that keep people from doing something at any particular moment. Phone call, cranky toddler, spilled milk, hungry cat–those things aren’t anyone’s “fault” and we press on through them, right?
How many years until we get to help you celebrate your PhD? I look forward to the party.