Behaved virtuously

Yasmin, Dustin, and Andrew are walking on York Road on Friday night when a fight breaks out among a group of young intemperate strangers. Dustin immediately springs into action, jumping in the middle of the scuffle. Andrew determines there’s no value in absorbing punches and heads home. Yasmin decides she can use her blackbelt jujitsu skills to disarm the aggressors and prevent serious harm. Who has behaved virtuously? Why he/she? Where did the other two fall short?