In the hospital where my wife works they would not have let this other Dr, without privileges, anywhere near a patient. Next, they would not have let him perform a procedure that was not approved by the patient.
The, not so obvious thing, about hospitals is that there are usually two or three people checking and cross checking these things in the operating suite.
This was done at a "private" clinic, of which there are many (still) on the Upper East Side of Manhattan. I imagine LA is the same, although I have no personal knowledge about the West coast.