Deliberate overdose with insulin in nondiabetic patients will cause toxic hypoglycaemia, including hypoglycaemic coma, neurological impairment and death (a delay between insulin injection and first medical treatment in excess of 6 hours is predictor of unfavorable outcome after insulin poisoning).
Hypoglycaemia can sometimes present with signs of a stroke, especially in older people.
Sorry, for asking, but, what's the nature of your interest for this subject?
Did you lose somebody due to this kind of "accident"?

My sister died, of a stroke, when she was just 49. She had been married for only two months to a diabetic. Her son knew she had made a will but no will was found. Her husband got everything. I just found the whole situation very disturbing and suspicious. Although all this happened a few years ago now, just recently I read the story of Claus Von Bulow and alarm bells started to ring!

Wow! That's so creepy!
I'm sorry for your sister.
Was an autopsy performed after her death?
Do you think she had certain risk factors for stroke?
I think autopsy is required before payment of insurance.