I guess I can't imagine a situation where Bill is contracted at a temp agency, turns around and hires Bob, and when Bob shows up with Bill's badge and is refuse

I guess I can't imagine a situation where Bill is contracted at a temp agency, turns around and hires Bob, and when Bob shows up with Bill's badge and is refused entry, and Bill somehow wins a lawsuit on the theory that Bill must be allowed to subcontract and anyone he subcontracts to must be allowed on-site to perform the work, no matter what. Like, not giving out your password (or badge, or key, or whatever) to someone else is a pretty core job responsibility!