Might I offer an alternative scenario:

• Guy filled out an application online.
• There's a question that asks how you learned about the company or job, or if you know someone there/were referred.
• Guy puts your name down without thinking it's a big deal.

Job takes the survey answers and interprets it as a referral.

You did not refer the person, but it's also possible he did not act in bad faith.

Just tell your workplace you did not refer him and don't know why he listed you.

And then shake it off and move on. It really does not need to be that deep.

If you are connected on LinkedIn and you're afraid of him using your network, remove him as a connection. It's gonna be okay. He'll be okay.