You really misunderstood the section you mentioned. Please read the last sentence "however, the pending adjustment application protects him from teh accrual of unlawyful presence". This sentence means the AOS protects the person from unlawful presence. In other words, the person with AOS is lawyfully present in U.S. even if he/she has no lawful status. Please note that lawful/legal status is different lawful presence. In many cases, you do not have a legal status, but you are lawful present.