SAHARA was one of the most advanced androids in the Prime's army. Unlike EMMA, he wasn't designed to keep unarmed civilians in check. He was an attack android whose only purpose was to infiltrate heavily defended enemy strongholds and destroy their assets. This mission was supposed to be a walk in the park for someone of his caliber, but he hadn't expected to encounter the cyborg so suddenly.
Kevin had taken SAHARA by surprise and struck him when he was at his most vulnerable. The android's eyes locked onto the cyborg as he kept falling. Seeing Kevin's mechanical body, he didn't quite understand why he was fighting for the humans instead of joining the machines.