Rinzler doesn't see when Prometheus arrives, but when he notices him skulking around the edges, there's a brief stare. If the enforcer were showing a little more personality today, it might even be characterized as challenging. He would've expected a smirk or sneer, at least. Prometheus was the first one to recognize Rinzler as broken, after all.

He doesn't notice when the malware leaves, but it isn't much surprise. The vote is meaningless, and even if it weren't, why should he care?