My understanding is that they strongly believe in no false positives, so it's definitely possible to slip something by them but if it marks something as AI, it very likely is.
Who cares what they "believe" (or, more accurately, say they believe). What are the underlying processes that actually guarantee this, and what data supports it?
Their 99.98% accuracy claim[1] makes me doubt that.
Much more importantly, 9/10 dentists agree it's the best.
1: https://arxiv.org/pdf/2501.15654, linked from² https://www.pangram.com/blog/third-party-pangram-evals (the second section)
2: the third study they link there is based entirely around the assumption that Pangram is correct, and seems to have been a collaboration or something as they're included in the credits area.