Choi Ri could not be prepared for that attack because the drum and Oliphant were destroyed and he could not know Goguryeo’s invasion.
At that time, Choi Ri killed Princess of Nakrang who destroyed the drum and Oliphant.
[5] Hodong was a child of Hae clan (Korean: 해씨; Hanja: 解氏) who was a stepmother of Daemusin of Goguryeo, so, the empress of Goguryeo afraid if Hodong become a crown prince by pushing aside her own son.
The empress gave a slanderous report that Hodong plans rebellion to Daemusin of Goguryeo.
[6] After that Hodong committed suicide because if explain to that slander, he could leap to light of the empress’s iniquity and Daemusin of Goguryeo would get anxious about it.