This is one of the reasons you try to keep the 911 operator on the line throughout the encounter. If you've made it to your defensive position there should be no reason to move. Put the phone on speaker and lay it down near by. That way they know where you are and you know where they are.I don't think I'll be calling the cops while I was armed, I'll wait until the dust settles. Cops have been known to show up shooting anybody that's armed, or appear to be armed, which is acceptable in most cases.
Paid admin leave, promotion, business as usual.
Worst case scenario, the cop gets fired from a low paying thankless job.
If that can't be done, be vocal... loudly. Communication in a tactical encounter is one of the key ways to avoid friendly fire.
The phone is also a good idea in case you have to use deadly force. They now have an audio recording of the encounter and that can help your case if there is any question that deadly force was needed.