You shouldn't be working if you're still sick or injured.
Rob has the coronavirus, but he needs to work in order to get paid.
Rob wants to work.
Rob lets his boss know that he has the coronavirus, so he is allowed to work from home.
Rob goes to work without telling anyone that he has coronavirus.
Rob's coworkers get to stay safe, and Rob gets to keep getting paid a salary.
Rob spreads the virus, and people end up suffering as a result.