Ummm, that is not what I would consider concurrent use. You are using GPS, a call comes in and GPS STOPS. You talk, then get off the call and then go BACK to using GPS. That is not concurrent use as I see it. If I am not understanding you PLEASE correct me.
Here is my idea of concurrent use... you are using GPS, a call comes in you put it on speaker and go back to GPS WHILE talking.
Understand, I am not calling you a liar but I want to make sure we are talking the EXACT same situation. If I am not understanding, please correct. I am more interested in getting the actual result then who is right/wrong.
You're correct, GPS will not work while on call, but it will pause/continue when you're done.
EDIT- actually, post above may be right. Your route is cached and GPS is a different radio so picking up a call is no problem.