Music blaring over 911 calls

[WPCentral Question]

I was driving home from work and as usual had my Lumia 920 linked by blue tooth to my car stereo to play music. On this day though some ***** was weaving in and out of heavy traffic and had driven up on the shoulder to force his way into my lane forcing me to slam on my brakes to avoid a collision. I got the guys plate number, stopped my music, and was in the midst of calling 911 to report him when the music came back on over the phone as soon as the phone started ringing making it impossible for me to hear the operator. Went to xbox music app and it said the music was paused. The stereo was off. No matter what I did the music would not stop as long as I was on the call. As soon as I hung up the music stopped. Of course 911 called me back but as soon as I answered the music started again and I couldn't hear a damn thing. I had to restart the phone to get it to stop. What the hell? Is there something I missed doing here? I've NEVER had it do this on a phone call before much less an emergency call. Is there a setting I missed here? Makes me want to get rid of this phone and pick up an android phone.