In the episode "Fault" was it really Det. Benson's fault the the little boy got killed at the bus terminal?

We saw the scene where Olivia get overpowered and hurt while pointing her gun at the guy who was using the little girl as a shield. At the station, Elliot blames her for not being strong enough to aim around and shoot him, and she undermineded the mission's success. There's a part of me saying that had Stabler been in the same position, he would've taken aim and shot him in the head because he's stronger mentally. Could it be the fault of both of them partially?