Welcome to HealthcareMagic forum.
I understand your concern. Hypoglycaemic event is not uncommon among type 1 diabetes
. It is most likely due to inappropriate insulin dosage or reduced eating. And hypoglycaemic can cause seizures.
Having said that, hypoglycaemia
following insulin usually occurs later in the night as sugars gradually declines due to action of insulin. If your boyfriend has the irritable episode shortly after insulin use, hypoglycaemia is unlikely.
Discuss with your boyfriend whether or not he has similar events in the past. His family/relatives may help you knowing this detail.
EEG both sleep / awake and video EEG record can be confirm the condition if you suspect any of the aforementioned conditions.
Hope this helps.