Because don't you think that in itself is a form of witness intimidation? Won't people be hesitant to volunteer to testify during a lengthy trial if it means a security guard literally watching them sleep and shower for months.
I meant not that the witness would be obligated to accept that, but that a company would be interested to offer to pay for various measures to preserve their health, sanity and all that.
But the claim was that he committed suicide, say you're concerned about the company killing you so you accept their security. Couldn't the security then just have a good reason to be in your house to "find the body" when you "slip in the shower"
So then someone else can kill him like others have said. But depending on what is being whistleblowed, someone in the company taking the fall for murder might not be as bad as what could be discovered. Especially if government agencies are included in this.