Hi,
@markm90 , and welcome to the forum!
Yes, that can happen but no, it doesn't happen often, even in diabetics having trouble getting reasonable numbers.
Before insulin all t1's died within months or a couple of years at the most, so simply not taking your insulin will kill you.
While your hba1c is on the high side, you've already showed a big improvement in the last year, well done!
Have you looked at how you can improve your numbers even more? What would be needed to do that? Have you done a carb counting course and are you testing a lot to find patterns?