Back in 1998 I had a psychologist who was supposed to "supervise" and then one day he took his 5th vacation in a year.. only this time he let me know in advance and low, and behold I was getting daysheets while he was out vacationing... when doing my own audit, I had seen it was done a few times, I turned him in and got whistle blowers payment 3 years later.. he's now an excluded provider. BE careful when dealing with billing of supervising providers!
I now require my supervising clients to sign off / initial on each superbill.