It might not be a written metric, but do you actually believe that someone isn't being evaluated partially based on how many times they've had to talk to them about issues?

I highly doubt it. If this is the reason your manager knows who you are, you are absolutely going to be judged on it. It doesn't really matter what the policy says.

And the nurses absolutely feel like they are being punished for it. Just like having to consistently remind HR that your "absence problem" is due to covered FMLA leave - they know who you are because they've had to talk to you about absenteeism. In a call center of 500 people, it isn't likely they remember that you had issues because of their faulty systems.