the zone read. Ollie Gordan is the main guy with potential to hurt in the run game. Batty taking the RB away in the zone read was probably his assignment. If Batty is trying to cover the QB and running back than Ollie runs for even more yards. The safety was probably assigned to the QB.
This is the reason the zone read is difficult to stop. Each player on D has a specific responsibility. If one player doesn't do their job right there is a big play. The big runs by the QB doesn't fall on Batty.