As Carl got up with Freya and Grey behind his back, Dave was following his orders. The orders that could make families reduce by half. However, if he grew a conscience right now, then a lot would be lost, and Ngelo would do worse than he just ordered.
It wasn't his intention to do it this way, but these people needed a lesson on who was in charge and who wasn't. They needed to be snapped back into reality in all the ways they couldn't fathom yet. The way to the storage room was filled with gasps from the people who had seen Carl and his chain.
Everyone knew what that chain did and while Angelo instantly killed, Carl loved to torture. He always believed that making someone feel the pinch of what they had done and how wrong they had been was the only way to get through all that.