More than likely, they had the forms there and someone would bring in a dog *or in some cases they would just fill the form out* and send it in to the insurance company. If the WC works anything like what I had to deal with when I got hurt on the job, the patient and the company fills out a form. Then the WC place says "Ok, go get treated here" Once the person is treated, then the place in question sends the Insurance place a bill and they pay. Since theoretically the only people sending them bills are places that have been approved, they probibly don't bother matching every person with every place. If they DID bother matching, its easy to send bogus request forms, get them back, and ship off a bill. Its @$$'es like that who make it hard for legitimate cases to go through.