my only input device to the medical records will be the AI transcriber
I understand that you keep steering away from legal arguments, but that can't be legal either. How could a doctor not have direct, manual access to patient records?
Anyway, practical issues:
You need some way to manually interact with patient records in the inevitable event the AI transcription gets it wrong. It only takes one time messing up transcription on something critical and you have a fucking body on your hands. Is your hospital prepared to give patients the wrong dosages because background noise or someone else speaking makes the AI mishear? Who would be held responsible in the case of mistreatment due to mistranscription? Is your hospital willing to be one of the first to try and tackle that legal rats nest?
A secretary is able to do a sanity check that what they heard make sense. AI transcription will have no such logic behind it. It will turn what it thinks it heard into text and chuck it wherever it logs to. It thinks you've called for leeches when you said something about lesions? Have fun.
Whenever there's an issue with the transcription service you'd be screwed too. That could mean network outage, power outage, microphone breaks, any part of this equipment breaks, and this whole system falls apart.