Bluetooth or iOS Bug ?

I have a bluetooth headphone (Sony) setup with both my iPhone 6 and my Retina Macbook.

I activate the Bluetooth connection Between the MacBook and the Headphone

I watch a movie on the MacBook and hear the sound from the MacBook in the Headphone.

On the iPhone, I decide to use Siri.

I Long Press the Home Button to Activate Siri

The sound of the movie form the MacBook stop

Now I can now hear SIRI in the Headphone.

I tell my command

and after SIRI respond, The sound of the movie from the MacBook return to the Headphone

I tried it a few days later and it still does the same thing...

I feel it is a iOS Bug, anyone had something like that happened ?