This is a question for Jon.
Bert, I don't see many question marks in your post

but I will take my best guess at what you are asking...
Our staff is trained that I should be notified if a referring doctor... or really any physician... is calling in. They might "buzz" me on my desk phone or send me an instant message that pops-up on my computer screen. I generally take the call, unless I am in the middle of a particularly intense moment with a patient. If I am doing procedures, I am not in the office and will would only see a message between cases, so I would call back after getting the message.
My experience is that specialty groups generally understand that some referring docs have a preference for a particular specialist and do not take offense at this. If I am calling a cardiologist, for example, I ask for my favorite by name. If he is not available, I leave a message (if it can wait) or talk to whomever is taking calls/consults if it is urgent.