Assisting against the wrong mob

Clearly says that I'm assisting against the war-weary storm giant, which uses different keywords than the guard. Yet, I tried this three or four times in a row and every time, I attacked the guard each time. 1 PM outdoor clear > assist groupmate You assist Groupmate against a war-weary storm giant. Your acidic bite MUTILATES a storm giant guard! A storm giant guard is covered with bleeding wounds. 506/96% 466/100% 716/100% 5344(62.89%) 1 PM outdoor clear > Your acidic bite DISMEMBERS a storm giant guard! A storm giant guard parries your searing cut. A storm giant guard parries your searing cut. Groupmate's defilement MASSACRES a war-weary storm giant! You dodge a storm giant guard's blast. You dodge a storm giant guard's blast. A storm giant guard's blast MUTILATES you! A storm giant guard is gushing blood.