As I mentioned before fear makes people do strange things.
Remember that the unvaccinated don't inherently spread covid. The infected spread covid which can be the vaccinated or the unvaccinated. Again people divert what our focus should be on by promoting the two camps of vaxx vs unvaxx.
Lets take a look how you would know someone is lying about their vaccination status:
1) They told you. So then to tell your boss would a betrayal of the trust of your co-worker.
2) You snooped to find out. How would you like that coworker to snoop on your private health business?
3) Someone else told you the coworker was unvaccinated. Now to tell your boss would be rumor mongering.
Their are any number of reasons someone might be unvaccinated. The individual may have other health issues that they don't want disclose that impacts there ability to get a vaccination. You have no idea why they may not been truthful of their vaccination status, but you are perfectly comfortable putting their job at jeopardy without knowing their reasons. That's F'ed up. The unvaccinated person could also have been previously infected.
We're not talking about someone committing a crime here, although I'm sure the left would love to criminalize not being vaccinated. Mind your own business. If your vaccinated don't worry about, and if your are worrying about it then you really don't trust vaccinations, in which case your Exhibit A for why they shouldn't be mandated.