Can you explain what facts you feel are incorrect. Your link is just a pdf summary of all material provided by the FAA. BMI cannot be the only factor utilized in the assessment. Risk assessment is supposed to be based on a variety of factors, but BMI remains a major component. The most helpful document link is
Guide for Aviation Medical Examiners
For what its worth I am a sleep doctor and I found these guidelines confusing.
The Spec sheets A and B are a link at the bottom of the document. Hope this helps. Also
ZEE APPNEA ? Sleep Apnea Risk explains this somewhat.