Pangram AI detection scans are mostly useless.
Method: Ran an unpublished 100k word novel written entirely by a human into Pangram, one of the most common AI checkers. I inserted 2 pages written by AI into it to see if it would find them. I had the checker run through each of the different chapters one by one.
Result: The book was listed as 86% human written, with 14% AI. The 2 parts that were actually AI (written by Claude) were not flagged. The incorrectly flagged portions mostly consisted of sections of professional business language related to characters talking about their work.
It seems what it's looking for are specific buzzwords and sentence structures commonly used in business and professional writing. These are normal constructions, and certainly common in AI, but also common in any professional setting. Basically, if you write with professional language, you'll be flagged as AI.