So I just did a bit of research on it and according to Wikipedia and several journals it seems to be definitely possible for someone to die from nicotine poisoning. The wiki article cites two child deaths. I also found at least one article where nicotine poisoning was deemed the cause of death. Warning, it does contain shots of ther person’s dissected esophagus and their stomach contents. There’s a NLM journal article that pops up on a child committing suicide by nicotine ingestion, but the article was missing. So I can say it definitely does happen. I just couldnt find any readily available mortality studies showing how often it happens.

As for anecdotal evidence, I had a client with Pica, who would eat cigarette butts among other things and be vomiting all night.