Though he'd squeezed Stark's neck in a tight grip, hearing Steve call out to him--with the same words he'd used in the sole memory of him the soldier had retrieved--made him loosen it enough to be tackled to the ground without bringing the engineer with the both of them. He landed on the floor under Steve with a grunt, his metal arm unable to move quickly enough to support him or throw the super soldier off so that he could properly get at his target again.