They informed me that no, he was on my team and were incredulous that I wasn’t managing him. I showed them that I had never received his name in any e-mail or Slack history since I started at the company, and no team members had ever worked with him. I messaged him in Slack to ask who he was working with, but he never responded despite being online.
HR was very secretive after that, but from what I can gather the employee was reorganized into my team but no one ever told me. He worked at a remote office, so he simply sat around waiting for someone to contact him with instructions for what to do next. I don’t know how long he managed to collect paychecks without doing anything at all, but he disappeared from Slack shortly after this incident.
HR at that company had other issues. I’m glad I don’t work there any more.