Don’t agree with 单身老猫.

If several doctor checks prove your friends are still capable of his job, company should not hold him from back to work. Because the company is holding him from back to work, you friends should act more proactively. Collect and keep all doctor opinions, contact  labor department, ask what rights he have, communicate with the company why he can not go to work. Keep in mind, your friend is 100%healthy because doctors had assessed him. The company cannot use heath reason to against him