It was a Fairfax unit with a Montgomery County paramedic on board transporting to Suburban. EMRC was a little confused because the MC paramedic didn't clearly state how he was contacting EMRC, and given that he was using the Fairfax units unit ID (correctly) EMRC wanted to be sure how he was contacting EMRC.
EMRC has a single Region V receive speaker that all the calling resources in Region V are tied to so users are trained to call EMRC and state on contact by what means they are contacting EMRC ("EMRC, EMRC, Fairfax A401E on 72C [soon to be 7H1] requesting a consult with Suburban Hospital"), so EMRC knows what associated resource they should be building the patch with (72D in today's case [will be 7H2 once we transition to the new system). If the user calling doesn't state how they are calling EMRC then EMRC doesn't know what radio resource to put in the patch. This is particularly true when a Fairfax unit is contacting EMRC for a consult because that doesn't happen too often.
The EMRC operator did a good job ensuring that he knew who he was talking to and how. The paramedic could have avoided the confusion by stating how he was contacting EMRC, but he was in an unusual situation transporting on a Fairfax unit and has probably gotten used to EMRC knowing what to use for the patch when he calls with an MC unit ID even if he doesn't state how he is calling in. EMRC did a good job keeping things straight.