There are so many levels to who CAN do what and what they're likely to do...there are Licenses, privileges and scope of practice.They're all different.
As a physician a psychiatrist is LICENSED to do an appendectomy - or for that matter brain surgery. However no hospital is going to give them PRIVILEGES to do anything other than practice within the scope of psychiatry. If they did an appendectomy or brain surgery it would be malpractice. (These kind of discussions relate to whether or not OB/GYN's should be giving botox - some are.)
Most internists (all I know) would be unlikely to feel confident doing an intrauterine instillation. I don't know of any internal medicine program that would teach intrauterine instillations. They'd refer it to the OB/GYN. It sounds to me like its basically an amniocentesis, but instead of withdrawing amniotic fluid, saline is instilled.
Could the Deans have received extra training from an OB/GYN and then done intrauterine instillations - Sure, their licenses would allow them to do this.
But having been through internal medicine internship, I believe it's more likely that they felt they didn't get enough experience doing even basic GYN procedures like pap smears and pelvic exams (that they would be asked to perform in a private practice clinic) and they were looking to get more experience at the very basics.
I could be wrong - but without any paperwork showing "privileges" for them do do intrauterine instillations, I can accept their explanation without thinking it's necessarily fishy. Others clearly think differently.
If Dr. SDean has no problem with abortion, what would be wrong with him releasing the records. It might help him.