From September 4 to 7, 2026, researchers proposed a new evaluation protocol based on the Walton argumentation scheme theory to test the defense quality of nine cutting-edge large language models against 200 highly ambiguous moral choices. The study analyzed 6,778 manually scored cells through a four-stage dialectical process and verified the reliability of the results with 89.6% judge consistency. The results showed that all models exceeded the standard baseline in defense across all dimensions, but failures mainly focused on the adequacy of arguments, and were related to epistemological hesitation rather than argument length. Additionally, the protocol could identify strictly irrefutable defenses such as self-contradiction and revealed the difficulties in AI alignment regarding the representation of retraction roles, suggesting that more contextual evaluations are needed in the future.